"Great stage piano, poor controller."

Feature:
Features are good, for what's there. You can program quite a bit and you get a few DSP effects like reverb and chorus. Like I said, there's not a lot of features, but it pretty much comes with everything you'd need.

Quality:
It's really stylish and seems to be pretty well-crafted. It's fairly heavy (probably in the middle compared to most), but nothing you can't handle in a car. If you're a city person and don't have a car, you should not take this on the subway, the bus, or in a taxi. This is a friend's-car-only device. I've never moved mine, except up the stairs when it was delivered, and I can promise you will not have a fun time getting it from point A to point B if you're paying the driver if I found it uncomfortable to move two flights of stairs (not that I'm a big strong guy or anything). It is well-made, though, in terms of craftsmanship. Like I said earlier about the velocity curves, it has some major issues, but aside from that I would say its solid build is its best feature.

Value:
Theoretically it's an excellent value but I feel like I could've put my $600 to better use for what I needed. I think it would've been smarter for me to get a Yamaha P60 or something similar. If you're in a rock band and you want a good stage piano, though, this is probably your best bet.

Sound:
The sound is pretty good for a stage piano but I wouldn't expect this to hold a candle to any sample libraries you can buy for it. It is one of the better keyboard piano sounds I've heard, though. While not perfect, M-Audio did a pretty good job. The main problem is that they used a Yamaha C7, which is a great pop/rock piano but I would not use it for classical applications or jazz. While this also doubles as a MIDI controller, don't get it as a MIDI controller for your primary function. The velocity curves (there are three and they're all bad) are awful and unrealistic. If the Yamaha C7 wasn't so punchy to begin with the built-in samples would sound bad. I've used lower-end consumer keyboards with touch-sensitivity that provided more realistic velocity metering than this thing. It really is the only VERY disappointing feature of the M-Audio ProKeys 88. The keys require almost too much force to press (in my opinion), yet very little pressure will provide quite a loud sound. I feel as if the graded hammer is wasted as the velocity hardly changes. It takes a very soft player to achieve a wide dynamic range out of this thing and I like to really lay into the piano. I play a little harder and louder than most, so it's a big problem for me. If you are very gentle, you'll probably like how the ProKeys feels, but I'm very disatisfied with that aspect of the piano. However, the built-in sounds are pretty damn good. I only use them when I just want to play (since I use this mostly as a controller--not the best choice), but they're pretty good and pleasing. I would not recommend the sound if you're in a jazz group unless you can run it through an EQ first.

Support:
I've never dealt with M-Audio support, but if DigiDesign is handling their calls now that they've bought them, I recommend praying instead. You'll get farther.

Overall:
I'm already not satisfied with it. I'm trying to figure out a way to make it work for me so I can keep it, but I didn't like it the first time I played it. The reasons my ratings are as high as they are is because for the right uses it is a great piece of machinery. I just bought something that's made primarily as a stage piano when what I needed was something more capable as a MIDI controller. I just wanted a MIDI controller with a decent piano sound so I could practice/play without hassle when I felt like it. If you're in a similar situation, DO NOT BUY THIS. If you're not in this situation, this is probably the instrument you're looking for.