Welcome to the forum. How much does the B piston 6.8 sell for? I personally don't mind totally breaking down my ARs every 500 rounds or so and giving them a good cleaning. Gives me a chance to look at the internals and replace parts as needed. Maybe I'm just old school but I like the DI operation. Good luck with you piston 6.8 I'm sure it will give you years of shooting fun.