I don't have a Tenacity but I do have a Rebel. Extremely well built, very tight tolerances and endless configuration options. I was able to pick my tenon length, tang, bolt diameter, bolt head, bolt fluting, bolt handle, right bolt, left port, port size, ejector style, specify feeding ramps to employ double stack 10 round AI AW magazines, metal finish, and rail.
I wouldn't hesitate to get another Defiance action of any sort again. I don't think you would find anything bad to say about it when you have it in hand.