I have a Tormek but no WS, but have been looking at them.
The Tormek is certainly going to cost more initially, especially with jigs. I think overall the Tormek is a better made machine and is more flexible. It deals with water which even though it does it pretty well, it can make a mess if you don't watch it. No question that it sharpens well.
The WS has the advantage of being cheaper and less mess. You'd have ongoing expense with paper although I would assume it is fairly reasonable. Supposedly the heat sink does a good job of dissipating heat so overheating is minimal risk if used correctly. From what I've seen the WS may do a decent job of flattening backs, which the Tormek will do somewhat but is really not a strong point IMO.
I think of you want to sharpen a wide range of items, a Tormek is great at that. It's expensive but it does it well and consistently. If you just mainly want to keep a set of chisels sharp and maybe plane blades, the WS may be the better route.