I bought a new bike two weeks ago and negotiated a discounted full fitting as part of the package. They switched out the stem at no cost to me. My cleats were re-positioned and handlebars rotated. The process took about four hours and it was the best thing I have ever done. I am 53 and the back cannot tolerate a poor position for more than 30 minutes. I did a 4-1/2 hour ride yesterday.
The fit is on your bike, with your pedals, seat, cycling shorts...etc. The fitting has follow ups. We raised my seat a few mils after a week. I am supposed to come in for a full review at the 90 day mark. I am very happy with it.