Not for sure on some of the answers but, I got a 16" CAR kit from them in May and have had no problems with it at all!!!
No QC problems with my kit, unless you consider that they sent me a collapsible CAR stock instead of a pinned, non-collapsible CAR stock. This problem was taken care of promptly, though.
There were also a few extra springs and detents in the kit, which could always come in handy!
The only other problem I had was the time it took to receive my kit. It took a few weeks for my kit to arrive, but at the time, there was a big demand for the kit I ordered, therefore it took longer than normal. There was also a problem with the finish that was applied to the upper receiver and barrel. But I was patient, as I would rather have it done right the first time, than to have to send it back after I received it, only to find a problem with it and have to send it back to be refinished again.
FWIW, I will be ordering another kit from them again. I have a MEGA lower that I am needing to build on, I just need to decide which configuration that I am going to go with.