Does it really matter if his processor is at 30C or 40C? Okay, he could probably do 10 degrees better using an actively cooled system of similar price, but what difference is that going to make? Sure, hypothetically his processor's life will be extended, but to what extent? It will last 20 years rather than 15? Who keeps a processor that long anyway? Or perhaps he could overlock more, 200mhz maybe... thats gonna give him an imperceptable speed improvement or an extra 12 3dMarks...
My point is that Watercooling as a hobby is about fun and fulfilling your personal goals. Sure, there are cases where you need it to cool exceptionally hot processors, but the majority of the time, its done for bragging rights, overclocking, or silence. If you visit
www.silentpcreview.com you'll find there are people there as crazy about silence as the people with Dual Phase change setups are about cold - its just a different direction.
I like this site because it takes cooling very seriously, but deep down we have to remember we do this because we enjoy it.