This is where I'd love to see an experiment in Zymurgy on mash temps and finished beer. Identical recipes mashed at different temps up to like 160, using the same yeast, and do some taste-panel analysis. Mash temp is only part of the equation in relation to the beer's finishing gravity and mouthfeel - yeast is huge here, I think. With something like US-05, even a 5-degree difference in mash temp may not be noticeable in the end.
Maybe this has already been done in a past issue?