Right now I am playing my Tyros as a midi slave, using as a master a Roland A-37 (76 notes, with waterfall keys). The difference in key fell is really remarkable (I like the Roland much more than the Tyros); plus, the velocity curves on the Roland allow me to play the Tyros with a lot more dinamics: I guess that not only the Tyros has narrower keys, but suffers also from the same problem as the old DX7, meaning that it's really difficult or even impossible to attain the highest velocities (like 125-127) from its own internal keyboard.