I have about 600 rounds through the pack without issue. This one breach block of mine has a rough spot, and was catching it on the rear. Once I swapped in the spare, it's been running great. I've run all flavors of 5.7 without issue including TMJ/FMJ. Make sure your mags are clean, and Dorin is now including some weapons grease for the bolt/hammer. At $450 for 4 components, I'm sure there's some profit built in, but the main components are 17-4 stainless. The safety selector is just marked "F" vs "A" as a CYA, and is the aluminum version they already sell.
This system utilizes the factory Gen 1 hammer cut for the forward safety/"auto sear". Vendor is trying to state this design (even though they haven't seen it) could cause OOB discharges, but given that it's utilizing and not defeating any of the 3 factories sears/whatever the technical term is, I think they're misinformed.
The preorder for these are up again: https://bit.ly/4uBckt7