Work good for me

Used one of the original plug-in-the-wall Pik units back in the '60s as a kid. Considered it a chore. 50 years later, with gingival issues, I didn't realize then how important it was.

The PLUS is a great product. Battery good for about 2 weeks of use (once with regular tip, once with pocket-pic, daily,) and a large enough water reservoir. You can safely ignore the poor guy who complained about the tip "spinning around" because he was too ignorant or stupid to actually insert the tip into the unit properly.

I recommend it to everyone. Gingivitis (which affects almost everyone, eventually) can lead to increasing pocket depths, which contributes to bone loss, which, if bad enough, will lead to tooth loss. Those scary pamphlets in your dentist's office have a valid point.

Not a good road to go down, unless you admire the toothless hillbilly look. There have been many published dental studies (I read about 40 of them on-line in the Journal of Periodontology) that confirm the efficacy of disruption of bacteria whether physically or chemically (by, say, chlorhexidine,) and the PLUS (and Pocket-Pik tip) are good tools in that ongoing war. Cheap at twice the price, but don't use it to remove ear wax (one study details how you'll rupture your eardrum.)

Update:

After about a month of use, it seems to be consistently good for about 2 dozen or so uses between charges.

Speaking of charging, someone commented about corrosion on the charging contact pins. It's true -- I noticed minor corrosion almost immediately. It would have been better if Water-Pik had provided some sort of plug/barrier to keep water out of the plug-in cavity, or, better yet if they had used an induction-charge system with no contact points or pins as do many electric toothbrushes and other devices (either would make the product slightly more expensive, the later more so, but it would be well worth the extra dollar or three.)

But, unfortunately, they didn't. Nonetheless, the corrosion problem is easily solved without buying any Radio Shack parts. Carefully scrape any minor corrosion off of the pins with the tip of a knife and use an inch of tape (anything that's about 1/2" wide) over the plug-in cavity to keep water out of the plug-in cavity while in use between charges.

Hopefully, they read this stuff and will either add some sort of (attached to the unit) plug or go to an induction-type re-charge method on the next version of the PLUS, if they haven't already concluded that one or the other is a good idea.

In any case, I still HIGHLY recommend the PLUS. It gets all sorts of stuff out of your mouth that brushing and flossing can't and don't.

I hate flossing. So any product that will step in for flossing part of the time is a great thing. I do floss the regular way AND Waterpik sometimes, and that is super clean. On the hurry day and I just feel like doing just one of them, Waterpik is a more pleasant experience.

This is a big change because I used to have a Waterpik brand corded large-tank-style unit and it was worse experience than flossing. It was huge, loud, a hassle to fill, had a short tube that could accidentally get yanked, and took one of my few outlets in the bathroom. I am comparing this new Cordless PLUS unit to the old one, not against other cordless units.

Noise - This unit is much quieter, but any water pump will make some noise.

Reservoir - The size of reservoir is perfect for me. Just enough water to do the job. If I need more for a really good job, it takes a couple seconds to refill. The reservoir is SMALL enough to easily be held, emptied back out, and to fit under the faucet in a small sink.

Tips - It came with extra tips with different names and shapes, but I just use the classic one. It seems sturdy, but can be rotated one notch at a time.

Ergonomics - Perfect. I don't know what more to ask for, but it is handheld, light and mobile.

Battery - Lasts longer than other electric toys of that power (like electric razors) and has kept charge so far. The fact that it has a battery at all means I can charge it overnight in another room with an outlet then use it in the bathroom for days. The thing comes with clear instructions to charge it like 24 hours before first use, and to NOT run it all the way down. Follow that and it will work great.

Price - considering the expensive battery, I see no problem here. Similar price to other electric units.

Water power - Ok, so this isn't going to take the paint off cars, but it does clean teeth. I use it on high, and if that won't clean your teeth I recommend floss.

My review is based on only 2 weeks of use, and experience with only tank-style units in the past. Having said that, this unit exceeded every expectation, and this style of flosser (cordless) is much better for me. Is it more effective than flossing? No, but it goes well with flossing or is a good stand-in.

I have used a traditional electric Waterpik for decades. It is sometimes the only way I can dislodge food stuck between my teeth, and my dental hygienist always comments that my teeth and gums are in great shape. But they changed the design of the traditional Waterpik and I wasn't completely happy with the new design, so when the tube on my (very) old one sprung a leak, I decided to try this one.

I have an electrical outlet inside my medicine cabinet, so I can charge it out of sight. It is nice that it can be used away from an electrical outlet; once I even used it to clean a spot in my toilet, holding it several feet away, of course (it did exactly what I wanted it to do!). But it lacks the real power that my old piks had, which made me feel the old pik was really doing the job. Still, it does seem to clean the debris from between my teeth; we'll see what the hygienist's verdict is in a couple of months. One reviewer commented that this pik is too powerful, even on "low"; I can't imagine! Maybe mine or maybe that reviewer's pik is defective?

I do NOT like the fact that water runs down the pik and into the charging portal; there seems to be no way to hold it to avoid this. Someone else suggested covering the portal with tape, which I have done, but it's something of an inconvenience. Still, at least the contacts have stayed clean, but it does seem that Waterpik could design a waterproof way to close the portal when it's not in use, or even a sealed arrangement with inductive charging. Whatever, the old electric pik was easier to control, just a tiny attachment on a long tube, easy to aim and didn't tend to send water down my arm and onto my pajama's arm like this cordless one does. This cordless is comparatively awkward to use.

This would be a nice travel Waterpik, as it is one piece plus charging cord, but it is somewhat larger than my very old battery-operated Panasonic Travel Oral Irrigator, which is not rechargeable but is similar in effectiveness to this cordless Waterpik.

I've been using this cordless pik for several months. I use it every night and charge it about once a week, for about 24 hours, and it has never yet run out of power.

All in all, I think I'll buy a traditional electric Waterpik next time.

I was ambivalent about buying this based on the reviews that I have read. I will say up front I do not have a Waterpik that sits on my counter top and plugs into the wall socket. I had one once and will never own one again. You pull on the hose and the unit travels across the counter. No I found that I like the cordless ones better. I have own the Waterpik WP-360W. It was OK but the battery pretty much had to be charged every week if used daily. It held just enough water to get the job done, it was hard to fill with water under the bathroom sink and I got about 3 years use from it until the unit stop charging due to corrosion where the charger plugs into the unit(This is because water spills on the connection).

I then bought the Panasonic EW-1270AC. This was fine for travel but it had allot of problems like the water cap always falling off, water leaking out when you needed to store it in the suitcase(always had to keep it in a zip loc bag to prevent the remaining water that was always there even after emptying in sink), the tip always falling on the floor as the way it was to be stored should have held the tip better. Allot of germs on the floor. Plus the batteries were not rechargeable. So even after reading the reviews on the new Waterpik Cordless Dental Jet I bought one. For the life of me I could not understand why so many negative and mediocre reviews on this unit. But I figure it could not be that bad as it was the number one seller of cordless water jets. Here is a little contrast and compare on the reviews and my unit the WP-450 Ultra;

1. It is so loud it will wake anyone sleeping. Coffee grinder loud!
** Yes I guess it is loud as it is near you ear while using! But not that loud to me(i.e. I am a bit hard of hearing) My woman says it is not that loud and she has great hearing**

2. The reservoir is so small it runs out in 10 seconds.
** Maybe this user has a leak in his unit. I use mine for about 30 seconds until all food is removed and I still have half of the water left. And yes I am using the High pressure setting. **

3. The tip is so mobile (rotates all over the place), you can't control it.
** Mine doesn't. Of course I have only had it a month. **

4. It is poorly designed, too large, and difficult to hold (Can't imagine if you have small hands).
** I thought it was well ergonomically designed. I have nerve damage in my hand that makes it hard to hold on to things and get tops off of bottles but I had no problem holding the WP-450 Ultra. I think it is most excellent! **

5. Poor battery life, long charge time, no charge indicator. After two uses I needed to recharge! (yes I let it charge up initially for 16 hours!).
** I have only charged my unit for 8 hours and have been using once a day for a month. I has not slacked off one bit in pumping the water out. **

6. Expensive, Poor Value: Price is ~70% higher than the WP-360
** Yes that is usually the case for older models. They usually do cost less than newer models as the cost of production is higher than years ago. It is actually 61.4 % higher in cost. The old unit uses Ni-Cad batteries as the new one uses more expensive L-Ion or NiMH batteries hence the higher cost and the L-Ion battery can hold a charge longer. **

7. Poor Reservoir Capacity -only 120 ml or 20% less than the already-tiny WP-360's 150 ml
** I do not know how you can say that. I fill my units up to max and the new Water Jet holds twice the amount of water then the WP-360. Also I had to use a paper cup the fill up the old WP-360 **

8. Terrible portability, large/inefficient size, ungainly ergonomics
** Well it is not touted as a travel water jet just a cordless one for home use. The Panasonic however is a true Travel/Portable unit as advertised. **

9. Weak water stream.
** You've got to be kidding. It has two settings and is way better then the WP-360 and about the same pressure as the Panasonic model. Are you sure you have it charged up? **

10. Very bad. Main problem is the tip won't stay fixed, it keeps rotating, so it sprays water everywhere but your teeth.
** I have not observed this problem. My tips stays right where it should. I will report back if this changes. **

11. The reservoir is so small that it empties before you are ready to stop using it. It should be at least 2 1/2 times the size.
** I have to wonder what you are using this for. I use mine to remove the food particles from the gums and between teeth. When things stop coming out of the mouth am done. My dentist says I have the best gums of any patient he has in his practice and I only use this once a day before bed. **

It appears that the problem with the old WP-360 was the fact that the charger contacts on the front would get water inside no matter how careful one was and the metal from the charger was different from the metal that took the charger. What I observed on the WP-360 was dissimilar metal corrosion. What I observed on this new water jet was the charger contact is now enclosed in plastic and has been moved to the back of the unit where their is less chance of water getting in to the charger contacts.

Allot of people keep going on about the old WP-360 in this post about the batteries not holding a charge. I think most people probably keep the unit charger plug in while not in use. This will lead to what is called a memory problem with Ni-Cad batteries. Ni-Cad batteries should never be keep on a continuous charge as that will lead to the memory problem mentioned. It is best to have Ni-Cads discharge completely and then recharge them. L-Ion / NiMH batteries do not suffer from this problem that I know of, but it is always better to only charge any battery after it loses its charge. Continuous charging on batteries will lead to shorten battery life.

If I experience any problems with the Waterpic Water Jet WP-450 Ultra I will amend this review. I just can not understand all these bad negative reviews. If the unit was so bad why would it be the number one seller when I bought it? No I do not work for Waterpic but I have used their products for years and have not had that many problems which is why I guess they are still number one in Oral Irragtor sales. I hardily recommend the WP-450 Ultra if you are looking for a cordless (not Travel sized) waterjet. This is hands down better then the old but still selling WP-360.

Updated 20 June 2016:
Been working great for the last 7 years!!!!!!!!!!