<< Upping the FSB shouldn't hurt your hard drives.
It can, and it happens. Your hard drive runs on the PCI bus. Unless technology has changed a lot and I'm really behind times, upping your whole FSB is effectively overclocking all your PCI peripherals as well, INCLUDING your hard drive. I have messed up a Seagate hard drive doing this. It still works, but it's very flukey.
So, if you want to overclock more safely, use the multiplier if possible. If not, well, I guess you have to take the risk. >>
Correct. I know Maxtor made some drives that were very sensitive to FSB, in the late Socket7 heyday.