Not a big fan of them for playing, either, Ian... but seeing as the style section has no proper Leslie, they do in a pinch.
Actually, the style section in the Tyros4 has several excellent Leslie sims (some even with variable overdrive/distortion)...it's just that I haven't had as much time to spend programming as I'd like.
I managed to get the styles in my S910 to do little beneficial tricks they weren't quite meant to do, so having the more extensive effects in the Tyros4 will certainly be an advantage.
Ian