My Beyer T5p had a lot of cable problems that required 2 RMAs within the 1 year I owned it. It doesn't help that the supplied carrying case is a cable breaker. But even without that the cables were pretty thin, which makes sense since it's something meant to be decently portable.

My Fostex TH900 pearl whites had a defective earcup hinge that I RMAd immediately after opening it and inspecting. That being said, it didn't actually break yet but would have been more susceptible to issues. On the flipside I've used my TH900mk1 every day for the last 7 years, and that's after I got them used so they're even older than that.

After Audeze was stolen from there was a lot of QC issues in the past too.