I've just got the 120 GB SE WD disk and it's just fine. My sys admin m8 complained about the noise on his old one (40 G I think). But as far as I can hear this one is pretty quiet, anyways the coolermaster CPU Cooler FAN makes more noise ;-), which is still not that much.
Another M8 also has it and he also says his is quiet as well. Warranty definitely has to be worth it, do you really want to be buy a disk which the manufacturer is only prepared to guarantee for one year, which unfortunately seems to be the case for a lot of IDE drives with +40GB platters at the moment.
One other plus point is the 120 GB WD disk is significantly cooler than most other drives I believe.