Both are great arrangers.

It basically comes down to a sampler vs. easy audio loops (not sure if the PA900 can put audio loops up on the multipads, or whether they tempo stretch), as much of the rest of the feature set compares fairly evenly.

Then it's 76 vs. 61.

For me, that alone is the decider. I play a LOT of piano stuff, and simply cannot handle being cramped down to a 61. Plus I like a fair bit of room for each side of a split.

Well, that, and that I've got a huge library of Roland Styles, and SMF's optimized to Roland. But either arranger is good.