I see a good amount of the Titleist guys (Walker, Spieth, etc.) are playing the 915 D2. Sort of curious why they play this model and not the D3. I've tested the D2 and it was significantly shorter for me: couldn't get the spin lower than 2700 rpm, average carry of 245-250, average total of 260-265. D3 on the other hand is one of the longest I've hit, and extremely accurate: spin around 2000-2100 rpm, average carry of 260-265, average total of 275-285. I'm sure my 105-108 swing speed is a lot lower than all the pros, so how is it the D2 fits them better than the D3?