Nick:
I agree and if Yamaha were to expand Motif Performances to support 6 parts I would upgrade. That would make the Motif even more exciting to use. Since I have a Tyros 3 I have been able to get more voices in a mix by using the Right 1,2,3 and Left on the Tyros. Plus I also use one or two channels in a Style combined with the Motif Arp parts.
Diki:
I agree that once you get use to a touch screen it can become a requirement. Although in my case I seem to have wide fingers and have had issues selecting the right item when I demo Korg products. I have found the Motif buttons to be be so fast to use with no accidental selections of things I don't want.