It seems like every Crown I've come across has had problems. From a CE1000 that had one channel just completely stop working to a powerbase2 that wouldn't turn on to even a macrotech shutting down in the middle of a gig, I've seen a number of them go down.
On the other hand, I've never seen a QSC go down.
Now this is really just anectodal evidence since my sample size is way too small for my experiences to hold any statistical merit, but personally I don't know if I'd ever feel comfortable buying a Crown amp.