It seems to me that Roland takes much greater advantage of aftertouch in its programming. In some sounds, it even controls pitch. Yamaha does not seem to take advantage of aftertouch it its programming.

The Fantom-S series also has the 16 drum pads that respond to both velocity and aftertouch--I believe it is even polyphonic aftertouch.

The Fantom-S series has room for four SRX expansion cards--for a great piano sound and interesting world sounds, for example. So I think there is plenty to recommend the Rolands.

OTOH, the Fantom-S series is not a good arranger substitute. No chord recognition and no provision for vocal harmony.