Hmmm, I was kinda hoping that it would let me get a little bit bigger cog on the rear with a 10 speed (every little bit helps).
I don't know if I can actually go bigger on the rear though, even with my present setup, without a derailer change. I know when I put the 27 on, some people thought it would work, but some weren't sure. Even when I wrote to the Felt company, they weren't sure. But it did work. Bigger may push me past the limits. I really don't know how to figure those things out.
Right now, based on your comments, I think the compact setup might work best.
Near as I can tell, the 34 in front would be virtually the same as putting a 31 on the rear - a full gear lower, roughly.
Of course, with a 12/27 like I have now, I lose a little on my highest gear - I do use that sometimes, mostly downhill though. But if I can go with an 11/27, my highest gear is a little higher.
Only negative I can think of is the same one I get when I went from the 23 to the 27 - the gears are more widely spaced, making it harder to find the "ideal" gear in some situations. Might be worth it though.
Would I be correct that the front crank couldn't have a wider difference than 34/50 without having problems?
As I said, I really prefer a double rather than going for a triple. It just feels more solid to me.