Running the card without ramsinks is fine. If you do add ramsinks, and for some reason you have to RMA the card later, it is possible that ATI will claim since the card was modified, so the warranty is no longer valid. Will it provide better cooling? I'd say quite a few of the ramsinks you see is more for looks than actual cooling. There are some ramsinks out there that could help in cooling, but without any OCing, its relatively pointless.