I have one, and I didn't think it worked too well with drops. Maybe it'd be slighting improved with bullhorns, since they're less ....errr.... drop? But still, I think that having those two protruding horns is going to limit what you can carry with it, especially if you're a shorter rider.

So while it can be done, I think that flats/drops are actually the best option for this (or any, really) front rack.