If a split rail has enough amps on it then there's no problem, it's when they DON'T put enough on it causes problems!
My PSU is quiet and hardly gets warm when playing games!
Using a wattage calculator I think in total I'm only drawing 380w from the PSU:
Asus Crosshair mobo
AMD 2.8GHz Dual Core with Arctic Freezer HSF
2GB Ballistix DDR2 RAM
nVidia 7950GT
SBLive 5.1
RocketRaid IDE Controller
3 x HDD
2 x DVD
1 x Floppy
5 x 80mm case fans
Wireless Mouse + Wired Keyboard
Plenty of watts left for when nvidia release the 9800