I would suggest also checking out the new Casio Privia line. They range from $495.00 to the PX700 for $700.00. If you need more than 32 note polyphony than I would suggest the Yamaha P90. I also have been told by the repair shop I use that the M-audio controllers have been known to not hold up very well and need repairs more often than most others.
George Kaye
Kaye's Music Scene
Reseda, California