as for if its better or not, hard to say. some games play better in sli, some play better with 1 bigger card. i switched from sli 670s to a single 780ti. i switched because i was sick of waiting for sli supported drivers for new games. some games i play worked better with the sli 670s, others with the 780ti now. unlesss you like messing around with custom sli profiles, i would stick with the single 660ti. less headaches. but with that being said, i probably will end up going with sli 780ti's, just cuz i like to waste money lol