I picked this up yesterday, and it is great.
I have the 25-key version (which I'm giving to Drew), and liked it so much that I upgraded my other 61-key (basic M-Audio non-weighted) to this guy so that I can use it with piano VSTs and as my remote control for Reaper.
These are solid, especially for the price (about $400, before coupons and such at MF). It feels really solid, is completely USB powered, the semi-weighted keys have good feedback, and it has a ton of lights on it.
Even the 25-key version of this is a pretty awesome studio tool. All of the knobs/faders are assignable, and the drum pads are a great side-bonus. If you're sequencing drums, it's nice to have a small set of decent-sensitivity pads to quickly tap a beat out in whatever you're using to write your drums with.
If anyone needs me, I'll be belting out Home Sweet Home like a boss.
These are really awesome for the price, great buy.