I have had no problems with mine. It has always ejected the shells it was designed to shoot. It will also eject light loads, down to 7/8oz, when I switch out the factory recoil spring for a shorter (cut) recoil spring. No broken parts either.
I do have a friend who somehow managed to install his gas piston backwards and touched off a 3.5" steel shell. With no way to vent ecess gas and pressure it threw the slide back hard enough to crack it. Not the gun or designers fault. I feel any gun out there would have the same or similar problems in that situation.
B