OK, I bought a 180B for $599, after taxes $638. I love it! I have fired 400 rounds +/- through it. I have owned an AR15A2 since 1990 and have a love/hate relationship with it. I consider the gas tube system of the AR15 a liability. The AR180B has a pushrod. The rifle does not get as dirty as the AR15. Also, the AR180 utilizes the AR15 trigger group and magazines. It weighs less, too. The AR180 appears to be a winner for Armalite.