Ditto from me too! I ride long rides- 50-75miles in carbon fiber sole shoes. I also have Superfeet inserts in my shoes instead of the innersole they came with as I need extra arch support. Another word- I use wool socks almost exclusively as they breath well in cold or hot weather.

Hard soles are best if you want to do century rides as you do get more support (kind of like a good mattress for your back idea).