Yes, over ten years ago Behringer's large mixing consoles had marginal or
inadequate power supplies. Smart audio engineers bought them anyway and
first thing ripped out the power supplies, put in a socket, and added an
external supply to feed the necessary DC power to the mixer. The last two
generations of Behringer mixers have been flawless. Quantum theoretical
levels of self-noise, no measurable distortion (on very high end test
equipment), and rock solid reliability even in educational settings.
Behringer products, from the past six years or so, have little if any
internal
resemblance to the competition. Different chips, different circuits, and
very clever original internal layouts. On the other hand, the internals
of most of their competitors looks pretty much the same - standard
off-the-shelf IC's, pots built into the circuit boards, capacitors of the
day, etc.
I'm not actually a fan but I think a lot of people round here make a big
deal out of Behringer products which doesn't meet the experience we have
on this side of the pond of using them. However it may just be that we get
better quality Behringer products on our side of the pond. Maybe it's a
supply chain issue or maybe it's something to do with the stockists.
Anyway I don't sell mass manufactured audio hardware in a chain of stores
so I don't have the stats to say if Behringer products have a higher
failure rate or return rate than other manufacturers.