Both of our boys got their first haircuts at Harmony Barbershop. It was great! We've always made appointments in advance. With my oldest, we were the only ones in there. It took only about 15-20 minutes or so, start to finish. With my younger son, it was a busy day. We waited about 15 minutes for him to be seated in the chair and the cut again took about 15 minutes or so.
We are rope droppers and we like to take breaks from the parks in the middle of the day. We like to make the appointments for lunchtime. We go to our appointment, then leave from there to have lunch back at the resort. So it doesn't really slow us down from touring since we already are leaving the park anyway.