Go for the XS rack man! Great patches in that box for sure... I guess it also depends on what type of patches are important to you as well. I know it's subjective but IMO Korg has amazing string and orchestral patches. Many of their orchestral patches have some killer velocity switching goin on Plus Korg puts some great Combi's together too.

I really like the Yamaha XS.., but I would have to say I think Yamaha softened up a bit and with this particular Motif model they catered A LOT to the acoustic emulation this time. It's got some nice synth patches.., but Yamaha took a big "acoustic" approach with the XS line. Not a bad thing either because there are some very nice acoustic patches in it.