I do a lot of barehanded in the summer, just haven't seen it as necessary, (well, sure, in a crash they're handy) until last month when I did well over 100 miles and realized I was getting a blister on my palm.

I suppose the solution is to ride faster so I'm on the bike for a shorter period of time.

I am currently using the Giro Monaco and they work well. I love Castelli stuff but don't like their mitts. One of the reasons I don't like mitts all that much is that they tend to push down on the webbing between my fingers. This is minimized by the Giros.