Just thought I'd throw in my experience of the formidable Hiper Type-R 580 modular PSU, for over a year it powered the following system:
ECS KV2 Extreme motherboard
2x1GB DDR memory
Athlon 64 X2 4800+
Gainward Geforce 7800GS+ AGP
2x WD Raptor hard drives
7200rpm hard drive
DVDRW
Front panel LCD
3x80mm fans, 1x120mm fan
After an upgrade about 6 months ago, it was powering:
DFI LanParty UT CFX3200
2x1GB DDR
Athlon 64 X2 4800+ @ 3.0GHz
Geforce 8500GT
7200rpm hard drive
DVDRW
3x80mm fans, 1x120mm fan
That was then put to work folding 24/7 on the CPU and eventually the GPU too... (it's my secondary machine at this point)
Then I got crazy and added an 8800GS to it a few months ago, that was folding too, 24/7.
About a month ago I replaced the 8800GS with an 8800GT and then that was folding 24/7.
Right now, there's an 8800 Ultra in there with the 8800GT. Yes, that PSU is powering this machine:
DFI LanParty UT CFX3200
2x1GB DDR
Athlon 64 X2 4800+ @ 3.0GHz
Geforce 8800GT (@700/1750/2000MHz)
Geforce 8800 Ultra (@700/1750/2300MHz)
7200rpm hard drive
DVDRW
3x80mm fans, 1x120mm fan
It's folding 24/7 and has been good for a few weeks now, I've never had a single problem with it and it's rock solid. In total I've had it about two and a half years so far and it's really been hammered, to be fair.