I also use butterfly bars and like them a lot. If your happy with drop bars though I wouldn't say that butterfly bars are a replacement for them though. There more of a superiour alternative to flat bars.

Here's my setup,



and



Now to start with I LIKE braking from the closer position so it works for me. If I'm in a situation where I think I might need to brake quickly I will be in position. The sides to me are like being on the hoods and the forward position is my equivelent to being in the drops. I don't have any issues in going to the brakes from the other hand positions but a little forethought is handy.

Regards, Anthony