I have had two procedures w/Dr. Beehner. There has been enough time that both have grown in completly. Am I satisfied with the results? Yes, because my expectations were realistic. There is an abvious cosmetic improvement.
Is it undetectable? Absolutely not. FU's were used at the hairline and look quite natural. As far as the minigrafts in the middle of the top of my head, if I seperate the hair with my fingers, I can see obvious "plugs", meaning there are several hairs from a small graft, a bald space, more grafts and so on. I comb my hair straight back and wear it several inches long. In that style it is not easily noticed that I had the procedure. This is beacause the hair combed back blends with the hair behind it and offers decent coverage.
Does my barber know I had an HT? Yes. Did I have to tell him? NO.
The bottom line is, I don't feel the result is undetectable as far as the mini's. If you want closer to undetectable, I would suggest all FU's by a skilled surgeon. That list would include Dr. Beehner. If I were to have a 3rd HT, I would consider him, however I would want all FU's.
I can't speak for anyone else's procedure(s), I just want to give a candid view of my own experience.