Dr Greg has been doing this a long time. I first needed a chiropractor about 20 years ago. I found one that seemed OK at the time. He was slow, but I'd feel better after a while. When I moved away from there I had trouble finding a new guy. After several different guys (and ladies) I found Dr Greg. Been with him for about 10 years now.
All I can say is that when he's done I nearly always feel better. If not immediately, then within a few hours. His methods seem to work quickly, and he's pretty good at finding little trouble-spots that are causing all the problems.
My only complaint would be that he's not open Tuesdays and Thursdays (but he will often come in anyway if you are having problems).