Nightbanana,
that's the $2000 dollar question.
I've played them all, and I think it depends primarily on what you want to do with the synth.
I owned
a Motif-6 for all of 3.5 weeks (when they first came out last year), and while I absolutely adored the piano and other keys, and the keys (playing surface) are absolutely the best on the market in the category (IMHO), I didn't want to work that hard to make music. For example, just playing a SMF-1 file requires loading by template and mapping to GM tones on the Mo. A pain....!!! On the TC you just load and press play. The TC also has killer Sax..
Now I'm in the same boat as you. Trying to decide between the Motif and Triton Classic (Studio is too pricey right now!) or the Triton rack. I like the TC's touch screen, hate the Motifs minimal display and layout, and have never used the TR (but it has the TS's 96MB Sampling memory, auto-slice and takes 7 expansion boards).
Since you mentioned that all sequencing will be via computer, I would consider the other I/O options on each. SCSI, Smartmedia, M-Lan and S/PDIF, etc. They all have them, but the first two (SCSC/Smartcard) are standard on the Motif, extras on the Triton.
And so on, add nauseum. I'm boiling it down to which sounds I prefer on each, ease of use/navigation on each, expandability and option prices. Right now the Triton Rack is in the lead [based on all the above, especially price (check Ebay)] and as I have two other boards I can use as MIDI controllers, I need to decide whether I want a controller setup or another set of keys hanging around.
On the support front - I have to say that Korg is still hovering pretty much around a 2 on a scale of 1 to 100. Yammy is much better - re:Motifator.com. But....., that said, there's a number of Trition sites out there (Triton Central, Irish Acts) that have some incredibly knowledgeable folks who can answer most questions, and the Korg US Product Manager is known to frequent them and respond.
Never had to deal with either manufacturer directly so no exposure there.
Let us know what you decide on, and the criteria you used for the purchase. I for one am real interested and still undecided.
Regards,
Steve