For an SFX psu, not having a power switch on the PSU doesn't bother me to much.
Depending on the case design (like my rvz01), you couldn't access the psu without taking the computer apart to access that switch. So unplugging the computer or holding the power button for 5 seconds would be a lot faster.
Now if this was an ATX PSU i would give a bit more care for as it's extremely rare for an ATX psu to be placed somewhere else inside the case that cant be access from the outside.
@10TACLE
I do have to ask though, does your computer lock up so much that even holding the case power button for the 3 to 5 seconds does nothing?
Most computers I've messed with seems to be able to power off fully even when there is a hard lockup doing that method.
But i do agree with you about that hitting a reset doesn't guarantee a solid reboot. Certainly when trying to dial in overclock settings.