Most comfortable upper i have grasped - Aero Precision AR-15 10.5in 5.56x45mm NATO No Forward Assist Complete Upper Receiver with Flash Hider w/ ATLAS R-ONE Handguard

Very comfortable to grip underhand, or overhand with a very close grip that is surprisingly comfortable. Definitely noticeable how much lighter and nimble it is compared to a full 16 inch. The lack of a forward assist is very pleasing. The only reason I am giving this 5 star item 4 stars, is because the fine print says that its a .250 outer diameter for the takedown pins. I had quite a fair bit of slop with this aero upper on my aero lower. So keep that in mind when building with this upper. I had to go back and buy an aero LPK, and while the front pivot pin was much tighter and offered very little play, the rear takedown pin still rattled around inside the hole of the upper receiver. I tested it and didn't even bother taking the buffer tube as a result. I ended up using a .003 shim that I found on a website and put it on the front pivot pin, and also used a accuwedge. Maybe I just got a poor fit and its not indicative of aeros typical product, nevertheless I am very pleased with the upper, even given the extra expenditure and frustration. Keep in mind, it is hard to find .250 OD takedown pins. If I could actually find anything in stock, I would have bought some double oversized pins and sanded it for a perfect hand fit. Hands down this is the best handguard at a minimum that I have seen on the market. Good luck in your purchases.