Originally Posted by
ArchEtech
As mentioned, I'd guess fit and posture is going to make a bigger difference than frame geometry for the average rider. Get a professional fit, and see if that solves the issue before convincing yourself to get a relaxed fit bike. I have a cyclocross bike that I set up for road, and its more relaxed and comfortable for me as compared to my Madone, but I notice more from the wide tires than anything else!
There is a lot to be said for the ride quality of fatter tires. You might want to check out a cross bike and see what you think of the ride; same goes for a touring bike. They may give you the kind of ride you are looking for.