Thanks, guys. Lots of good info here. I think rather than convert my touring bike I am going to put together a new bike for local sub 20 mile bike rides and try swept back bars, maybe occasionally loaded. That way I can assess the wrist issue, wind resistance, before making a big change to my touring bike.

I did ride my hybrid yesterday for a couple of hours and it felt like a whole lot more work than my touring bike but I have a hard time believing this was because of wind resistance alone--never really like the geometry on this bike so time to try something new and experiment with handlebar configurations.