I've had my BF D-2 Enhanced Special Edition black T bladed Sifu now for about two months. At first, if I locked it open gently, there was some vertical blade play, but not now. The lock button has moved towards the blade end when open a wee bit more, so it has "settled in." There is a slight off-centeredness to the blade, but not much, and I will someday loosen, bend and tighten the scales to correct this (if what I have read here works!).
I carry it quite often, but it hasn't been to my health club's bagel table for a while (all my new Spydies have needed to be bagel-baptized).
Someday I will get another in ATS-34, if I don't get a new Savant first! If I have to send it back, oh well. I consider these things to be more "Ferrari" than "Chevy." From what I've read, I do wish REKAT would correct problems before sending new knives out, though. But I can't complain from my one experience.
I'm very impressed with my most expensive knife purchase!
Karl