The two WS's I use at the moment are a K2500S (and X at the studio) and a Triton. Both are great studio tools, but live, I prefer the convenience of the arranger. They just seem better set up for live. But sound-wise, no contest... A modern TOTL WS (MoXF, Kronos, etc.) can take on any arranger. But those bloody chord following arps just don't cut it as an arranger substitute.

It was reported maybe two or more years ago that Tyros Mega-voices vary quite differently between arranger and WS lines. The Left Hand of Yamaha, and all that! Someone tried to play a T2 into a Motif ES Rack. they just don't line up. But if something can remap them, you are good to go. From what I have read, Yamaha's WS's keep a pretty consistent map between their models, so I imagine that if you map for a MoXF, you probably have XS and ES covered, too...