I have usually bought drivers off the rack, and tested them, and then sold them and tried again.  This time I wanted to get a proper fitting.  I currently use an I20, just wasnt happy with the consistency.

I went to the fitting, warmed up and met the fitter.  I wanted a 910D2 or D3, went thru all the shafts and different heads.  Finally settled on an 8.5 deg 910D2, with the loft set at 7.75 deg.  I would have never have even tried an 8.5 degree head, I always bought at least 9.5 deg, and usually a closed face.  With the 8.5 head, I was able to hit med high very straight shots, that hit and had plenty of roll, all of my drives over the last few years would have no roll out or very little.

Bottom line, I now believe in the process, I came away with specs I never thought I would have.  It was an eye opening experience.  I ordered the 910D2 8.5 with the RIP 60S set at C2.

Just sharing my experience.