I have played both, and PvP in WoW (or controlling your char) is much more in depth than in SB. The interface has a lot to do with it.
You can JUMP in WoW, you don't have to click click click to move.
Don't get me wrong.. I LOVE the SB idea. But the gameplay isn't there. It's a step up from a M.U.D. and that's it. We live in the 2000s so the game should look, and have the gameplay of a game that belongs in this century.
I said before.. Mix the SB Idea with the WoW interface and you got gold BABY! Plus what's the deal with everyone in SB rerolling chars every other day.. That's extreme PvE.