I wasn't sure about this when I bought it. I went ahead and got it without ever seeing or playing one, and I was immediately very impressed. First of all, it's built like a tank with metal housing and it has a very solid feel. At music stores or with equipment that I've owned or currently own I've played about everything with weighted keys and these keys are better. The keys don't have aftertouch but I don't care because I have other boards that have that. The feel and action is awesome and much better than anything I know of that's out there. On my Yamaha pianos, the action was good at first but then the keys would get noisy and it became really annoying to play them. Even after replacing the keys on my Yamaha keyboards, they would get noisy again after a while.The keys on this are still nice and quiet just like they were on the day it arrived, and the keys always inspire me when I play it. The pitch bend and modulation wheels are lit which helps when it's dark, and they also feel great. I power it with an inexpensive AC to USB adapter and I've never had any problems at all. The slider can be assigned to any MIDI controller number that you need, but I just leave it set for volume because when I play several rackmount synthesizers at once, once I get a good mix, I can turn them all up & down with that slider and the mix stays the same.There is (of course) a sustain pedal jack, a jack that can be used for a soft pedal and there's a volume pedal jack too. It has MIDI out which many keyboards don't have anymore.