I have mine facing up right now in my case purley for aesthetics. When I have some time I can run some tests and see if it makes a difference. We all used to have our PSU's sucking hot air from the enitre case when everything was mounted up top. I still have PSU's that are running fine from those days.
I just built my new rig with the Silverstone TJ08B-E and the PSU is mounted at the top in that case with the fan pointing up so that it's pulling in outside air. My old case also had the PSU at the top, but the fan was pointed down pulling air from the inside. Just throwing that out there for informational purposes.
That case mounts the motherboard upside-down, so that would make sense to me.
Perfect! Yet the TJ08-E and PS07 manual (Page 6) suggests the opposite..."fan facing down". There you have it, it makes no difference. END OF THREAD
Anything. Everything. Name it!