The Triton does suck for piano - never been Korg's strong suit. For synths, pads and the like - it rocks.
The Roland is a nice keyboard. Almost bought one, but decided to hold off for a while - gotta slow down sometime! Really nice organ stuff and the pianos are decent. It's got the really light-weight type keys - good for organ, bad for piano IMO. I prefer weighted-keys for piano work, but you can still get the job done with the lighter keys.
The MOTIFS are great too. Nice pianos, nice "rhodes" type sounds, useable organs. I spent a couple hours tinkering with one in a local keyboard store, and really liked what I heard. I own an S80 - which still is a great board and the MOTIFS do sound better than the S80.
Good luck to ya! If you have a local store, I'd head out and play around a bit to see what might work for you best.