Both are good.. Corsair PSU's are better quality than their OCZ counterparts.. So for a 10$ difference, i'd recommend the Corsair model.. BTW, you don't require a 650W unit to power a single 5770..
yeah, but you leave the possibility open for a 2nd 5770 or a better, more power hungry card in the future. I wish I had bought a 650w instead of 470w, as now im limited in my upgrade path unless I replace my PSU also.