af120's were nice. Super quiet; nice air flow, would use 8-10 Fans and couldnt really hear them at all. Now I have some of them rigged on my desk through front I/O port of PC so they face me, nice cool breeze while I sit at PC and again, very quiet.

My main concern when switching the fans was the temp changing a lot on the S1's but they only went up 1-2'C which I was fine with considering the substantial amount of sound reduction that came from the swap.