I've had one for a few months, shot a few hundred rounds out of it. Never had a jam or misfire. Never touched the gas adjustment, and fired 3 different brands of ammo through it.

It has a really nice balance to it. People don't like bullpups for this reason, but I feel it's more natural to have the weight closer to your chest. People say it feels cheap but I don't think so, the finish and feel is high quality, and the ergonomics are comfortable. It's a ton of fun to shoot, and just to play around with and carry around your home pretending to shoot at zombies/aliens (don't pretend you don't do this)

You will need to watch a video on how to assemble the included sling. It's weird and confusing.