Well to assist you in your choice here is my experience.
I purchased
a Triton LE 76 for my wife to write on. She has been using
a Roland E 500 which was an awesome keyboard in its day, but is now a little long in the tooth.
We had the Triton for about 10 weeks, and during this time did not successfully manage to utilise the sequencer or to fins any nice sounds that suited the style she was writing in (country, pop, ballads, etc). We had many nights of tears, many posts on various Triton forums to try getting help and the manual from HELL was of no real use.
I managed to find a store here who would exchange this monster for
a Motif 6 and what a difference it has been.
The sounds are awesome, the sequencer is logical, we now have the added benefit of sampling, and although my wife is still learning how to use this properly, there are no longer nights full of tears and she is managing to write and be inspired once again.
The Motif forums on the net are great, providing much usefull information.
In my opinion (and mine only) I would steer clear of the Triton and go the Motif. You will have to go listen and play with both to make your own decision. I think the Triton may have been great in a live situation, but as we are recording 99% of the time the Motif for us was a far better choice.
Cheers
Richard