I recall some time ago, there was a some discussion about these here, but don't recall the specifics, and can't find it here. I just ordered one of these because I hate staking the nut into place and screwing up the threads on the buffer tube.

I'm ordering the K2 with the locking lever. Now that some time has gone by since their introduction, has anyone tried one? Any issues to be aware of? Gimmick or