Towards the end of my first summer riding as total ride times started going over 3 hours, I would get hot spots in one or both feet. I was using a good pair of Specialized MTB shoes and SPD pedals. Switched to a pair of Sidi's and a set of 6620 Shimano's and no problems since. That was my primary reason for switching shoes and pedals.

I can't really say there was any performance advantage, except that I don't think I would be as comfortable doing sprints or hard uphill attacks with the SPD's I started with. I am not familiar with the ATAC's, but I do have total confidence in these pedals to not release at the wrong time.