Well my take is the PA1x pro has the most realistic sounds, especially playing them solo for recording purpose.

The Tyros has the most realistic sounds when mixed within the arranger styles playing, they work well together,

The Roland is a bit like the Tyros, but I'm going on the VA7 sounds, not the G70, the Roland does the best with midi files sounding the best, but with solo voices they seem a tad weak,

Hope this helps