@samdu
1) Weight. When I got my aluminum case, I was blown away by how much less it weighed.
i see that as ONE problem...
there are so many whirly viabrating things in the case, that when they spin the entire case viabrates with them! the heavier the case, the worse the viabration + noise!
so IMO lighter cases are noisier
2) Heat management. Aluminum cases run much cooler than their steel counterparts.
if you have a well designed case, especialy a full-tower, it shouldnt be much of a problem!
As for quality, the aluminum case I have is an incredibly well built case. This is not one of those areas where heavier means better built.
IMHO, i havnt seen any really good aluminium cases... not compared to the steel ones!