After reading the posts in this thread, the OP honestly has no reason to get new fans except for the fact that he simply wants to. If you need high speed, high noise, high CFM fans, go get some Deltas or Sunons. If you're looking for a tolerable level of noise and plenty of good temps, just keep what you have on there already. I honestly have to say that past 1500RPM or so (120mm fans) for some coolers, you hit the law of diminishing returns and end up with too much back pressure that it actually ends up screwing up your temps.