While this thread is about the comfort of different style bars I feel what made my touring bike much more comfortable was buying a better saddle. I have very little natural padding on my sit bones. Now I find myself less concerned with my drop bars and can ride faster and for a much longer time.
New saddle:
http://rideonsports.com/itemdetails.cfm?ID=465
For the record, I have flat bars with Specialized bar ends on my MTB and Cinelli 61 drops on my road touring bike and I'm not completely happy with either.