I think of you guys are not understanding the implications that come with overclocking.
Some do not care about CPU life span (bit like me) But if you run a application which max out the cpu then the phone will get really hot and may damange other components near it and including the phone's housing.

I pretty sure 900mhz is stable but when at load there is a lot of heat and battery goes fast, saying that when the phone is in normal use, web/music/calls it seems to be better with battery life with 125mhz range