I stripped mine te day I got it because of the storys of possible bolts loosening. Cleaned the lube from the threads with alcohol based brake clean, blue locktite'd them, snugged them up and not one has come loose in just over 1000rounds. I have never had a single feed or eject failure that wasn't due to shooter error (not fully seating the mag). The absolute only issue I ever had was using too thick lube on the hammer assembly causing weak hammer strikes. It caused primers to extrude/blow outs. I verified it being a lube issue by repeatedly pulling the hammer out, cleaning, switching oils, assemble, fire 10 rounds and repeat. I run Lukas 15-40 on the bolt/carrier and light triflow in the trigger group. Flawless. I've now fondled a many AR's and none came close to having as nice of a trigger as my xcr came, after a little trigger work its really amazing. By the way it's seen hundreds of rounds down to -34c and it's also been so hot I've seared the palm of my hand touching the barrel. Maybe I just got lucky. My other shooting pals guns are picky about ammo and which mags run properly. So far I can run Winchester white box hollow points, pmc fmj, AE red and AE193 on setting 1 with 100% reliability.
I'm not doubting there were problems, flaws and qc issues with the earlier guns but everything has teethng issues, thousands died because the the early AR's issues. It took years to sort out the AR and it's also been a while since anyone posted here regarding an issue with a newer xcr.
Put yourself in robinsons shoes, he's got a new rifle on the market in this era where people are impatient, rude and demanding, people are insulting himself and his employees. He simple had enough and said if your going to call us ans be a #### your request goes to the bottom of the pile. If I had a rude customer call me I'd tell him to shove his car up his stink hole and refuse to sort out the problem.