The key problem depends on the individual. When you first buy the board the action is great (especially if you've been used to the Yamaha PSR line). The keys are bigger and have a longer throw. However after time they tend to develop a little mechanical buzz. It's not bad, and doesn't get in the way of playing either. If you play at very low volumes it will drive you crazy, but turning the board up 1/2 takes care of it, and for lower volumes you would use headphones anyways. I've also spoke to some that haven't had this problem too. I find that odd though. My MZ-2000 even began to do the same thing shortly before I sold it.

Squeak