All three doctors are great, but I feel each is best at Strip surgery. Konior is great, and well respected on the forums, and of the three I prefer him, but he has a long waitlist of about a year. Have you considered traveling abroad or are you planning on staying in NA? FUE is pretty expensive here.
ARTAS is really interesting. While it started out as a harvesting tool, it actually now makes recipient site incisions as well (!). It may well be the future of surgery, but I personally am not 100% comfortable in going with it now. What's also unclear to me is how ARTAS results differ from surgeon to surgeon...does it commoditize the surgeon? I'm not sure. Personally, I'd like the technology to continue maturing...