Mine didn't blow up, probably because I only had it in for about a week before I read the horror stories on here and put my case-supplied PSU back in (which, incidentally, had about the same ratings as the Q-Tec, despite only being 350W compared to 500W.)
The Q-Tec was sooo loud despite being advertised as 'quiet'. When I got my first decent PSU, I was amazed by how heavy it was compared to the Q-Tec.
All makes of PSU can die, though... I think the problem is not so much that Q-Tecs die more often, but rather that when they expire they tend to take out everything connected to them, where a good PSU won't! I'd never run a system with a cheapo PSU these days - easily worth spending the extra £50 for peace of mind.