Unless you're running a computational program, most things will not run your gpu to overheat. Manual setting of your gpu fan easily solves any overheating.
A true waterloop will run a system much cooler than A air cooler, with near silent operation. But again, theyre $300...
High end cpu cxoolers are precision machined with 4 or mor heatpipes yada yada.. However the difference etween a good cooler and a great cooler is bout 5C.
Heres reviews of the corsair stuff:
AnandTech - Corsair Hydro Series: H60, H80 and H100 Reviewed