My current rig is a Triton (Classic), A Trinity TR-Rack, Kurzweil Micro Piano, and a Hammond XK-3.
Let me tell about the Triton from this user's stand point.
I waited and saved and waited and saved to get this board. I own a Korg 01w/fd and a Korg X3, I have owned a M1 and a T3 so to say that I was a Korg man would be an understatement. When I purchased the Triton I also purchased the upgraded Piano card and the vintage keys card.
I am not really that stoked with this board. The pianos are useless unless you run them in stereo OR you enjoy listening to a synthetic hodge podge of bad sampling. The electric pianos are weak. There is no real rhodes sound. You just have to make due with what they gave you. Under the headphones, It sounds GREAT. Live, not so much. I purchased the Trinity rack for its electric piano and the Kurzweil for the grand piano sounds.
What does the Triton have going for it? Well, that all depends on the type of music you play. The keyboard was most definitely design for the hip hop world. The strings are excellent, so are the brass. The synth sounds are ok. The organ sounds were bad enough that I purchased a EMU B3 Module prior to getting my Hammond.
Now, you are probably wondering why I kept this board? Well the sequencer is the bomb. The touch screen is phenom and as a controller, you cannot ask for better. I just wish that they would have spent less time trying to come up with the 10 gazillion sounds they put in that board and just got the 15 or 20 essentials right.
I have played the Motif ES. This is a really nice board. The power supply is a little flimsy. The person that I know has had to replace the internal power supply twice at this point. This is not a good thing to have to do if you are a busy musician.
These are only my 2 cents. Your mileage may vary...
Wolfram