Surprised me - TRYBE Defense AR-15 Fully Assembled Upper Receiver Type II w/ Dust Cover & Forward Assist

I've gotta say I was immediately impressed with this receiver. It was a perfect precision fit with my X-Caliber lapping tool which made it lap perfectly. Then the take-down pins matched perfectly with my Seekins Precision lower and with very minimal play between receivers. As someone who always buys premium billet receivers for my own personal builds, it says something when I chose to keep this receiver for myself rather than using it on my brother's build. This was an impressive budget option and I am about to buy another.