H's bolts he's working on are going to have a key machined into it instead of bolted on (I think, I know hes working on one like that but I don't know if it's the only one he's working on). Those will also be match grade quality with a better lock up. I've got a Young Mfg bcg in mine right now and I'd say it's really a good piece of kit. I'd say the LMT is good also but the enhanced bcg, if I remember right, is made to bleed off more gas, so if your rifle is gassed right (not majorly overgassed), it may cause short stroking issues. The enhanced bcg was designed for the really short barreled ARs that have pressure problems during cycling.