Looks are great for roadie stuff. I've tried other pedals, but always come back to Looks. I don't get hotfoot, even on centuries. A good choice, IMHO. As for differences, you get more adjustability and less weight as you go to nicer pedals in their line. I'm sure there's more to it than that, but that's what I noticed when I was shopping for pedals a few months ago. If you ever walk around in your cycling shoes, though, I'd suggest getting some cleat covers. The Look cleats are plastic and will wear faster if you do walk on them much.