I've had some mixed experiences with American Guns & Ammo.
Years ago, I bought my first centerfire rifle from them. It was an M1917 rifle made by Eddystone in November 1918, still in its military configuration. The barrel was original to the receiver and had some pitting from corrosive ammo but otherwise didn't look too bad. I haggled down the guys running it at the time (Joe and Buddy, from what I can remember) and got the '17 for what was a reasonable price at the time.
I took the rifle to Rio Salado and proceeded to fire it for the first time. The first issue with the rifle was that before I could drive the bolt home on the 5th round, the wonky magazine spring would pitch the cartridge out of the action. Every. Damn. Time. I was frustrated that my '17 did not function as intended, but it fed and fired CMP M2 Ball without extraction issues. After replacing the faulty spring with a NOS one from Numrich, I came back a week later and ran some Remington Core-Lokt rounds from Bass Pro. To my dismay, I repeatedly could not open the bolt without pounding it with a rubber mallet a range officer had given me. The softer civilian brass (but interestingly, not the harder military brass) had bulges and scratches on it when I did manage to eject it. I took the rifle back to AGA and explained that they had sold me a defective rifle with a horribly pitted chamber and that they had not disclosed this to me at the time of purchase. AGA immediately refunded me.
I never did buy anything from AGA again. It is my understanding that Joe has sold AGA to another individual and is no longer involved with the operations of the company. Since they moved into their present, larger storefront, I have been back only once. Their inventory is purged of the milsurp they once had and seems to be almost only modern guns. Their prices have gone way up too. A 500-rd brick of 22 for over 60 bucks? No thanks!