While Roland's professional grade XP series will allow you to adjust every nuance of sound and instrument to the nth degree, the problem is you have to master music, engineering, and composition to do it. Enter the Roland FP5
If you're looking for the ultimate piano keyboard that sounds like an acoustic, and has a real piano feel, then consider the FP5. The grand piano selections are excellent, and the organ selections are also very good, although the draw bar operations is a bit disconcerting. The electronic keyboards are not to my liking, but the keyboard comes equipped with all the MIDI-2 sounds, which makes up for the factory presets.
But what really sets this keyboard off from most others is the 80 rhythm patterns! I've used most of Roland's professional keyboards, and the FP5 has blown most of them away with the rhythms! Why? Because for the first time that I've seen, professional quality rhythms have been implemented that follow your chord progressions instantly as far as I can tell.
These are high quality rhythms that blow away anything Casio or Yamaha ever conceived. You'll feel like your in a real time session with studio professionals. Play your favorite song without the rhythms, then select an appropriate one, then play it again. You will be amazed as to how good your song sounds, and how much better you will play it with a professional rhythm accompaniment.
Note that the onboard speakers are somewhat limited. Fairly passable bass response, but less quality in the mids and highs. You'll need headphones or a quality outboard speaker system to realize the full sound potential. I personally use Roland satellite speakers for the mids and highs using a JVC 50W/2 channel amp, and a Roland KCW-1 Sub woofer to punch through on the bass.
Overall the FP-5 provides professional quality accompaniment and excellent quality piano sounds. Your music skills will improve considerably using it.