Would you play mainly with headphones? If so, then do you really want onboard speakers?
If you're looking for more sounds and MIDI capability, I'd say there are better options for much cheaper than the P255. The Casio PX5S comes to mind.
If you're looking for more sounds and MIDI capability, I'd say there are better options for much cheaper than the P255. The Casio PX5S comes to mind.