I had the headband portion snap in two while climbing out, once. It just snapped, and fell off my head. I wasn't pulling on it, it was always taken care of, the works. I re-fastened it using a roll of electrical tape in my flight suit, and continued.
A couple of months later, one ear went out. THat was very annoying, and I got with an avionics shop on the field. They called lightspeed, and overnighted it to them. A day later it was back, with a new headband, new earcup, new chord and powerpack, and completely refurbished. All I paid was overnight shipping in each direction.
I should add that this wasn't a new headset when I bought it. It's the 20K model, and these were being sold at quite a discount to holders of flight instructor certificates. It was used and a trade-in when I bought it, and they still treated me like I had purchased a new product from them. First class, rapid service, no questions asked. For the money, they're very hard to beat.
My only real complaint about them is that they don't do well in high-noise environment. In that particular airplane, the headset couldn't keep up at takeoff power settings, and would go nuts, making loud unusual sounds. Once the power was retarded, the headset worked fine. I don't think it's likely that the headset will get used in an environment that noisy very often, so it's probably not normally an issue.
People are still burning to death in plane crashes this day and age.