I had tusq pins on my Alvarez that had become damaged over the years. Been looking at these for a while and figured I'd give them a try.

They sound just as good and bright as the tusq or bone pins do but are much easier to change the strings on. No pin removal tool or broken fingernails needed.

The low E was a bit tight with Ernie Ball Earthwood medium lights. String ga is a 12 as they recommend too. The rest went in smoothly though.

I have larger hands which was troublesome getting things installed but that's due to the guitar sound hole, not these pins.

Okay, so I didn't have any issues with these. But I did notice when I was threading the string through that each peg had different hole sizes. Make sure to look for this if you run into any problems, they are built for specific strings. Small hole to large hole.

Instead of changing out the plastic nut and saddle for bone/Tusq on my new Epiphone EJ-200 SCE I opted to try Power Pins first and I'm very glad I did. I have been playing and working on acoustic guitars for over 50 years and I have a large bunch, but only two go-toos; I just ordered a set for the second one I like these so much.

I took my sweet time on the installation to make sure everything was just right. On this particular guitar I could only use one washer (without the lock washer) because of the thickness of the bridge.

I have old ears but I could still hear the obvious difference as soon as I put that first E string on and tensioned it; louder and lots more sustain. The jumbo body solid top Epi has a great sound as it is but any guitar can always use a little tweaking. That said, I'm not sure I would use these on high end guitars such as Martin, Taylor, Gibson, custom builds or the like because those are engineered for the best sound they can get.

I bought Power Pins primarily for increasing the performance of the instrument with the ease of string changing being priority #2. I can tell you that it cut down my actual leisurely string installation time by 50% or more. IF I were in a rush, which I'm usually not, it would be even faster.

I perform 2-4 times a month so time will tell how these things hold up but I have no real concerns other than being unable to install the lock washers. I think the next time I change strings I'll put a little dab of locktite on each one just for insurance.

So what you're getting here is increased guitar performance and faster and easier string changing. Power Pins are all that the manufacturer says they are. If you're serious about your guitar's sound get Power Pins just for that.

Mounted into an Alvarez AD60CK with onboard active electronics and piezo bridge. Sustain is noticeably longer (presumably because the pins cinch down the bridge against the soundboard effectively clamping the parts together solidly. The additional mass did taper off the top-end brightness that tended to be almost brassy in the Dao wood version I have. Now it's rounder and fuller-sounding, much more dreadnought style, which is fine for me (I have a smaller Yamaha AC1M I use when I want more of a classical bright sound.) Harmonics are also noticeably clearer and ring without any overtones (12, 5th and 7th frets are all very pure now - they used to have an odd metallic ring that was fine, but odd to me.)
This is strung using coated Elixir Light 80/20's. Typically they've been warm and round, but the new pins definitely increased overall volume. Mounting for me was pretty simple - they are marked (and packed in-order) with (T)reble, (Mid), and (B)ass letters on them in pairs (mostly for string diameter accommodation - the overall mounting depth is the same for all 6. Width is about 1mm less than the regular plastic pins they replaced, so they should work on a 12-string setup, as well (as long as the extra 2cm length fits the bridge. (basic dimensions 5mm dia. at the teardrop bulb, x 20mm long to the tip of the tear.)
The instructions caution not to over-tighten them, so I used only to the point where they wouldn't turn/spin without definite torque, and they sit fine without buzzing.
I'd make it 5 stars if one or two were fitted with a 2 semi-tone drop to facilitate alternate tunings, since it's pretty easy to do given the well-engineered design and mounting they already have. Otherwise, works as advertised, and though pricier than plain old pins, they do give a semi solid-body style performance to most plain acoustics. Key is, the better engineered the guitar already is, the less farkles like this are warranted - i.e. don't stick them into Martins.

I bought these out of curiosity for my Mitchell MD200S.

The first thing that I noticed was that restringing is WAY easier and faster. You don't need to worry about the pins popping out on you (if you installed everything correctly) and you don't need to push the ball of the string into the guitar. It works much like the bridge on an electric guitar, just slide it through the back.

The second thing that I've noticed is that it DOES NOT CHANGE YOUR TONE, which I think is fantastic. I like the sound of my guitar already, and I really didn't want to change it.

One potential problem is that installing the power pins was a pain. I had to enlist the help of my brother to hold the pins inside of the guitar for the first two pins. The screws are made to be hand tightened but they are really quite small and hard to handle, and its hard to get the right adjusted just right for the bridge of your guitar (Putting in the pin, taking it out, adding/removing washers, putting back in Ect...). But even with the trouble, I had them installed and good for playing in about an hour.

I would definitely buy these for another acoustic guitar, mainly because of the better restringing. It makes a decent convorsation peice too as it seems to catch the eye.