Experiences with X-Caliber Barrels?

I've been looking through previous posts about this manufacturer on reddit and other forums but I haven’t found anything substantial yet. Does anyone have one of their barrels for the ar10/lr308 platform? How does it shoot? They have a lot of options available for only $270, and reviews of their bolt gun barrels look good. I would be using it with an Aero M5 receiver set and Toolcraft BCG.