3 of my shooting buddies are all rocking these, but with the 18" barrel, I've had some time behind one of them, it will need a mega cleaning once you get it, they are jam packed full of oil and grease, it did have a little bit of a break in period, tolerances may have been a smide too tight, he also experienced some issues with LAR mags not feeding properly, we tried 3 different brands, I told him to polish his feed ramps up good and he thinks it might have solved the problem, he's had no issues with p mags,
The second buddy just got his and it's already on the way back to the dealer, either the lower of the luth stock was out of spec, you could not charge the rifle, the charging handle would hit the stock right away, if you really tugged you could get it to come but then the charging handle and bolt would stick to the rear unless you manually pushed the charging handle forward again. So he got a bit of a lemon which is too bad considering the price.
And third buddy has also had no issues that Iam aware of, it's been all cerakoted a different colour now and seen many rounds.
Also if you plan to play with the adjustable gas block at some time turn the screws every 50 rounds or so, after a few hundred rounds it took a torch and a day of penetrating oil to get them to move