Exactly what I was looking for.
I had never been professionally fitted for irons before. Wanted a skilled fitter and trackman to determine the optimum based on a accurate data re dispersion, smash factor and spin. I like my iron heads so just interested in shafts. Hit 10 $@!#% with my current clubs then tried about 8 other shafts to get an overall feel then started to zero in on what worked best. Trackman showed significant improvement between current and what we decided upon.
So expert fitter, nice facility, lots of choice and Trackman. +++