Ok, I have BB 1.1 with the 1Ghz Kernel. I have SetCPU installed but the only profile I have enabled is the failsafe profile to put the CPU to 600Mhz and the Governor to powersave @ 55C.
I've noticed the only thing that gets my CPU anywhere near 55C is wireless tethering. Otherwise anything else I've done only gets it to 40-45C. Which is what I'd get at stock temps as well.
I know that Pete's BB disables SetCPU on boot - which is fine with me but if I ever start tethering I can manually downclock the CPU and/or at least have the Failsafe running.
Does that sound good?