piano_ex, Roland's lead sounds are the worst compared to the the rest. However, their acoustic sounds are simply unbeatable (ie piano, strings, woodwinds and brass). Roland's acoustic makes Yamaha and Korg sound terribly plastic! And what you heard is only the factory Roland sounds. Their expansion cards are way better.
So in the end, it's what type of music you're going to play. If you like the controllers in the Korg so much, you can always get a Roland module just for the sound. Controllers is a preference thing. Korg's controllers are suited for electronic music, hence the ribbon etc. Roland's joystick is a good all-rounded use. But I prefer Yamaha's wheels as they have pitch and mod separated in 2 vertical wheels. Best for sampling orchestral music when mod wheel control is very crucial (and I don't want to have accidental pitch changes everytime I use the mod wheel).
And as for the "combi" modes, I think it's again about getting used to it. But I do think Korg's combi mode is slightly better as well. Yamaha is simply user-unfriendly. Roland's also require some programming, but once you get used to it, it's OK.
Iansoh, I looked up energyXT. It looks like a standard DAW program. Did I miss something?
Getting late (almost 2 am). Baby fed, diapers changed. Now to sleep...for 3 hours until the next feed. It's been a while since I did this...