When I first installed the Orange bolt it fit really snug. (not in a good way.) I took it over to the crony and it performed worse than my stock bolt. I removed it from my marker and started to look it over. It was very rough you could see the machining marks, not near as smooth as the stock bolt.
Air efficiency? not sure I did'nt use long enough to check.
Quiet? not really, just a different tone.
I would not recommend this product to anyone who is looking for an upgrade to the dm6 stock bolt. It looks cool, feels lighter but doesn't perform any better. Trust me! use the money somewhere else.