Do not get me wrong, YS Tech fans are fine equipment. They are *very* strong at pulling air. Indeed they are *a bit* more silent than Deltas, but not by much...
All depends on the noise level you're aiming for. If you couldnt care less, take the YS Techs, it's the best bang for the buck when it comes to high flow (in 120mm). Beware as they are *very* powerful they can burn mobo connectors out.. If you take a heatercore -which is bigger than a BiX - you can try and get a 172mm fan, Comair Rotron or Papst come to mind there.
Now if you want quietness, the best are Papst with the NGL, N/2GL then NGML series, closely followed by Panaflo with the L then M series.
PS: my nick is "gmat" like "gee - mat" and not "gamut"
It's my UNIX login.