Just yesterday I flushed my system and replaced all the tubing. I also, just for experiments sake, turned the rear fan around so now it blow out the back of the case. So the intakes pull in the front and the rear pulls through the rear rad (makes the rad easier to clean) and out the back. I also altered my water loop to accomodate this change. The water comes out of the pump, into the warmer (because of the motherboard heat draw) rear rad, then down to the lower cooler rad and up to the cpu, gpu, nb, and back to the res.
http://picasaweb.google.com/bbopptec...10795143071106
Surprisingly the setup cools better! The mosfets are 3C cooler and the CPU, GPU, an NB have all dropped 1C as well. So it did make a difference and I'm glad I tried it out finally.