Had a chance to shoot it a bit this week, 25 rounds only, on paper at 50 yards, inch and a half group high right, could not find Allen key to adjust at Range, then 100 meter gong, five for five by aiming a bit low left, not sure exactly where I hit on gong...but sound and movement very satisfying. Not disappointing at all for first time out, hard for me to shoot well off hand, used to pistols, guite a bit of weight difference. You should find the lower you have works well. Seems like a solid A grade for function, and fun.
Stand shoulders square to the target with a thumb over bore hold and butt high on the shoulder will make shooting the AR easier. Far different ergonomic mechanics to holding an AR then a hunting rifle. However once you master it and the comfort level increases you will quickly become efficient in shooting the "modern sporting" rifle.