I really liked the idea of easy detachable fan for cleaning instead of having to unscrew everything to clean it or blow compressed air all over the place just to sorta get the job done. And although it wasn't ultra popular it the sorta looking to please enthusiasts attitude that wins people over; after all if they were all just the same cards with stickers slapped on them there would be no reason to buy one brand over another except in terms of warranty and support.
My overclocked Galaxy 460 has been chugging along all these years with no problems. I'd like to be able to say the same about this 660 in a couple of years.