I shoot Brown Bear all the time. I clean my piston guns about every thousand rounds or so.
Hmm. Do you know if yours has a chrome chamber?
Mine has less to do with the DI vs. piston issue than it does with the fact that I have a regular unchromed chamber. The chrome reduces the friction and allows the case to slide more easily out of the chamber.
My DI AR never had a problem, even when relatively dirty. I was scared of it at first, but when shooting brass it seemed to run reliably indefinitely.
I considered switching to a piston system with an anti-tilt buffer, but as the round count grew and I didn’t have any problems, I figured it wasn’t necessary on my gun.
In fact, even in DI configuration, even when dirty from running Tula, the bolt comes back with such authority that it yanked the rim off of the stuck steel case once, before I figured out the “mix the brass and the steel” trick.
Have you had any carrier tilt issues with yours? That seems to be the only drawback that I have heard of with piston conversions...