Interested in opinions on the correct way to select the right iron shaft. Went to an iron fitting, once we got beyond the shaft length and a need for a more upright lie angle the only thing the fitter seemed interested in was the swing speed. We tried numerous shafts and hit 6-8 balls with each shaft. The fitter picked the shaft based on which shaft i swung consistently the same speed. By consistently I mean +/- 1mph of each swing through the 6-8 shots with each shaft. If the swing speed changed 2-3 mph that shaft was eliminated. Wondering if anyone had a fitting based so much on swing speed and is this a common way of choosing the correct shaft?