Mine arrived as well and I love it. Its a beast for sure. It opens smoothly and locks into the detent as it should. I do feel the bumps of the hot rolled finish as the detent ball rolls over the uneven finish but I'd still call it smooth, not gritty or troublesome.
I'll probably switch the pocket clip to the other side so when the knife is in my left pocket the blade is facing forward. That is just my preference though, not a flaw.
I only have a Sharpmaker for sharpening. Will that do anything at all or is this steel just too hard? I'm curious to hear peoples suggestions on sharpening the REX 121.