I've run it. Not a lot - for now, only two sessions of DW and one of another game using the same engine. But my experiences are quite different than [MENTION=83822]Sanglorian[/MENTION]'s.
I find DW very easy to run. It requires nearly no prep and not that much work during play. I have fronts, a basic sketch of the initial situation and players' input - and everything else flows naturally from there. The game is fast. Rolls are simple and they always drive the story forward, both when successful and when failed.
On the other hand, running DW smoothly requires unlearning several habits from traditional RPGs. The whole background should stay flexible, so that you can react to players' decisions and rolls (for example, never assume that a place is safe and contains nothing of interest). When you need some details, just ask players and build on their answers. Don't be afraid to make hard moves, but remember that damage is among the least interesting. Don't depend on keeping secrets, as you have to give honest answers when player moves succeed. And so on.
The GM agenda, principles and moves are probably the best part of advice I ever encountered. It really explains how to run this game, instead of assuming that people know how to do it. And following them strictly really helps the game, even with an experienced GM.