A buddy on the next street (retired US Army Lt. Col.) didn't do any reading before he bought his ATI. He is only into 1700s-1800s muskets: about eighty of them.
Brand-new from the gun store it malfunctioned about once every three rounds as I watched.
All ammo was new retail US brass .223.
It has been over half a year since we tried to use it, but it seemed that the problem was with extraction or ejection. Can't remember which, but I was baffled.
I'm glad that other people solved their ATI problems (if so) but I wouldn't gamble my money on an ATI "AR clone", having no skills to evaluate and diagnose problems.
The buddy knew it was a gamble on the lowest-cost version, didn't mind the results, and he never returned it during the warranty.
On a side note, my former
S&W M&P Sport II, bought brand-new, functioned perfectly, all 400 or so rounds. AR rifles never "grew on me", but that brand-new S&W, bought in '15 or so was a perfect operation and highly recommend them, for what it's worth.