I have been using butterfly bars for the last few years on my Thorn Raven Tour. Last summer I crossed the Icelandic Highlands and found out that on rough roads, especially going downhill, you don't really have enough leverage when your hands are on the brake levers. The grip is just too narrow. I am going to try some riser bars and Ergon grips with the longest bar ends next. On tarmac and tame gravel roads the Butterfly bars have worked great. You have a lot of hand positions to switch between and you can stretch your back or sit upright depending on where you grip.

Magnus Thor
Iceland