I also had a chance to handle (and literality destroy) an AR-180b. I am sure it is the one that your speaking of. The side charging handles style. The one thing that I did notice was the metal covering the top (formed sheet metal upper ) of the weapon. Seemed to be a little light to me. Also I suppose to be legal it had the flash hider/ suppressor as part of the barrel. Looked like it was a continues piece of the barrel. The other parts looked pretty good. Think I would still go for the regular AR if it were affordable. Just my .000002 cents worth 
