I like it. The major problem with any new class is gaining acceptance and enough players to keep it going. The equipment limitations ate simple and easy, and most players have an old blowback and shake-n-shoot sitting around. If not, a 98 is about $50 on BST, $5 for a hopper, mask and tank can be carried over from open class.
I wouldnt write any rules for barrels. KISS. Simple rules = easier to adopt.
Case in point, I thought UWL was a great concept until I started reading about classes and gear. Nothing against those guys, just not for me so much.