> An additional advantege of the ATX is, that
> you don't need an additional CPU fan, because the CPU get's cooled by the
> normal power supply fan.

 ASUS does not fully comply to the ATX "standard" defined by Intel. 
For this reason, the CPU is not in the air flow generated by a regular
ATX-PSU - an additional fan for the CPU should be used. The difference
between an ATX-PSU and normal PSU is that the normal PSU blows the air
out of the chassis and the ATX PSU does suck it in and blows it into the
computer. A special chassis is requied anyway. The full length slots
are ony one benefit.

> ATX is the way to go for all new boards.

 Indeed is - but only if everyone complies to it.

-- 
Markus Illenseer