1. Against Toss it's almost always a win, especially if you go all in (attack using queen and half your drones). Unless he's got a closed wall with cannons, he can't stop you. In my experience, no-one does this in just about any league.
2. Against Terran, it's very succesful, if not quite as succesful as against Protoss. If they put up a bunker with marauders, or they micro 2 or 3 marauders behind a wall, you need to fall back. But in general, it works amazingly.
3. Against Zerg it works very well, as long as they don't six pool - if they do six pool and you haven't scouted it then you are in trouble. But in general, it worked well.
Bottom line? Although it seems like it's similar to the traditional zerg rushes, it's actually a very impressive rush. I would say that well executed it's got a 90% success rate on maps with short to medium rush distances. So definitely give it a try :)