I will be honest, I am not using this as a baby monitor. We are using it while my father who has Parkinson's is recovering from a bad fall and needs our help to mobilize. We wanted a way that he could call for us if his door is closed and we would hear him. This was the best idea for us especially since many of the "elder care" devices cost 2 to 3 times as much and are more of an alarm system than a monitor. He can call for us, and also we can speak to him before we enter the room.
I am not sure how well this works as a baby monitor, but I can say the sound is great, the battery life is very long and it has worked well for us.

UPDATE 6/4/13 - I'm keeping the Vtech rating at 4 stars. This is due to battery life. I can get about maybe 6-8 hours out of a charge, which is not very much. I'm guessing they really cheaped out on the battery. It does beep to alert you when the battery is running low. As long as you remember to plug it in every evening, it's not a problem. Otherwise, it's a fabulous unit and has been working excellent for our family. Still the best choice of the 3 I reviewed below.

UPDATED 3/28/13
I've owned the below 3 units over the course of the last 2 years. I recommend the VTech for now (I've only had it a few weeks, but it is by far the winner in performance AND value). For features, I only listed the features that I felt would be important to the average buyer. Some of the units had other features that I didn't list because I didn't think there were critical in my decision making process.

Also, it might be important to note that we live in a 2 story house and we have Wi Fi.

Philips AVENT Basic Baby Monitor with DECT Technology
1 star
Price I paid: $95

Features:
talk back - yes
night light - yes
battery backup on Baby Unit - yes
Temperature - no (but available on upgraded units)
Visual sound indicator - yes, LED

Ease of use and customization of features (ie: setting the sensitivity level, etc): easy, intuitive.

Signal: excellent, DECT, crystal clear

Other thoughts: Loved this monitor until....... after about 6 months of use the parent unit would randomly turn itself off with no warning, no beeping, nothing. I started waking up in the morning to an "off" parent unit. This happened even if it was plugged into the charger. When I pressed "on", it would power up just fine and work well for a few days. Then it would shut off again. After a few weeks, it started shutting itself of more and more frequently. Thought it was a faulty unit, so I called Avent and they promptly sent out a replacement for free (nice customer service!). After few months of use the second unit started doing the same thing. Therefore, cannot recommend this product - it's dangerous if it turns off while you're sleeping. If you run a search on the reviews for this product for "turns off" you will see that it has happened to others.

Angelcare Baby Sound Monitor, White
2 stars
Price I paid: $59

Features:
talk back - no
night light - yes
battery backup on Baby Unit - yes
Temperature - yes
Visual sound indicator - yes. But it's not LED (which is very bright), it's part of the digital display, so you probably wouldn't notice the bars lighting up. So, yes, there is a visual sound indicator but it's poorly designed rendering it not useful.

Ease of use and customization of features: HORRIBLE, clumsy, not intuitive. You WILL need to bust out the manuel everytime you want to changes something. Channel selection is done at the Baby Unit, not the Parent Unit. That means if you have a bad connection, you have to go into the nursery to change the channel and possibly run the risk of disturbing a sleeping baby. You have to go through a series of random steps, pushing buttons in a certain sequence on both the nursery unit and parent unit. Also, it doesn't scan the channels to seek the best connection. You have the manually go through and listen to each channel and decide which one sounds the best to you. Sensitivity adjustment is also done on the Nursery Unit. Temp display is bizarre. If you turn the Parent Unit on AFTER the Nursery Unit (which is about 99% of the time, since I, like most people I know, just leave the Nursery Unit on 24/7) the display shows the channel. And will stay on the channel until the temp changes. So, the only way you can see what the temp is if the temp changes. It would have made a lot more sense to have the channel appear on the display first and then time out and default back to the temp setting since I think that as long as you're getting a good signal, you don't really care what the channel number is. But you probably do care about the temp.

Signal: 8 channel 927 MHz frequency. Started off good but after several months of use, the reception isn't as clear. I've tried all the different channels, but I still get intermittent static. It's annoying because it wakes me up.

Other thoughts: display on the parent unit is BRIGHT. Some may find it annoyingly bright if you like a really dark room. I originally thought this was a good value (at the time of purchse, my point of reference was the $95 Avent), but now after owning the $29 Vtech, I think the Angelcare is totally overpriced, especially considering how difficult it is to program the features. Not acceptable.

VTech Communications Safe & Sound Digital Audio Monitor
4 stars (if it holds up, I will change to 5 stars)
Price I paid: $29 (Value!!!)

Features:
talk back - yes
night light - yes (nightlight also has "auto on" feature which is kinda cool)
battery backup on Baby Unit - no
Temperature - no
Visual sound indicator - yes, LED

Ease of use and customization of features: easy, intuitive.

Signal: excellent. DECT technology, same as Avent. Now, I've only had this unit for a few weeks, so hopefully the quality doesn't start to go downhill after a few months. If so, I will post an update.

Other thoughts: this monitor also has a "vibrate" feature, which I thought was interesting. On the parent unit, you would not be able to tell it's on if the room is dark because the display screen is not backlit unless you are actively pushing a button on the unit (I assume to save battery power, it goes into a "sleep mode"). I wish there was a small LED indicator for this. After my Avent experience above I have trust issues ;). With this parent unit, I have to reach for it and push a button so the screen lights up to confirm it's actually on. It's minor, but I think worth mentioning. The Avent monitor had a small LED that was lit when it was on.

For the price, the clarity, the features, and ease of use, VTech wins hands down. It has all the same features and clarity that the Avent had (actually, the Vtech has even more features with the sound alert and vibrate alert), but it was 1/3 of the cost. So, unless it starts shutting itself off, this is a FANTASTIC monitor at a FANTASTIC price.

I just purchased this for elder care, my elderly mother yells my name several times during the night & I would have to get up to see she she needs, sometimes she wants to know what the thermostat is set for"¦ this baby monitor has already saved me from getting out of bed, I can answer her from wherever I am in the house. Sound quality is better than expected.

Does what it's supposed to do.

My wife and I sleep in separate bedrooms And this device May. makes it easy for us to communicate with each other.