Steel Fiber I80 / I95 Iron Shaft Comparison

I've read a lot of posts on the web about people's preference between the I80 vs the heavier I95 shaft. I decided to give them a try so I ordered a couple so I could make up 2 7i test clubs. Before I started dry assembly I thought I would take some measurements to compare , so i dry fit the clubs as if I was going to make a set from 4 - 7i. The measurements found are as per the manufacturer tip trimming instructions. Both shafts are Reg flex. They were both the same length and 85 and 100g respectively raw weight. To help understand what might be the reason for the different readings, here are the shaft profiles from the Wishon Software. CPM figures are for 41, 36, 31, 26, 21, 16, and 11".
I80- 0 209 245 282 357 501 933 Butt Freq - 294
I95- 0 209 244 292 372 538 943 Butt Freq - 294
Dry Assembled Readings - 5i length of 38" 1/2" between shafts, no tip weights.
I80 - 4i= 0 " tip = 276cpm, 1/2" tip = 278, 1" tip (Tip chart rec) = 280cpm
5i 1.5" tip = 284cpm
6i 2.0" tip = 288cpm
7i 2.5" tip = 292cpm

I95 - 4i 0" tip = 287cpm, 1/2" tip = 290, 1" tip ( Tip Chart rec ) = 294cpm
5i 1.5" tip = 297cpm
6i 2.0" tip = 301cpm
7i 2.5" tip = 306cpm

So the question is , are people picking one over the other based on swing data resulting from shaft weight , or is it the obvious difference in shaft profiles / stiffness, or a combination of both? Discuss .....