Not really.  I went from a 910D3 to a 915D2 and there was no noticeable increase in distance on the monitor, but the accuracy was the deal closer for me at the fitting.   Has a lot to do with the shaft and I tired a multitude of shafts in my hour long fitting.  I like the accuracy.  

I think you should go back for another head to head comparison analysis.  The 913 is a great feeling driver, but produces much more spin than the 915.

Truth be told, I like the feel of the 913 better.  The 915 feel hot and gives a sensation that the ball is rocketing off the face but the 913 is softer.  I suppose that is simply preference.

the numbers however were very different.  The 915 gave me much better spin and launch just not distance.  As far as accuracy, I hit both drivers in very tight dispersion and usually straight.  I truly love my driver !  Like everyone else, I just wanted more distance...

I did go thru the fitting twice thinking something could be off with the simulator.

I was hitting the 913 D2 and went for the fitting for the 915D2. I only gained a few yards with the 915 D2 and the spin was a little lower. My typical flight will have a carry of about 280 yards. I had two shafts for the 913D2 which were the Aldila RIP & the Project X shafts. Changed them out from time to time but the yardages seemed to be the same. Currently play the 915 D2 with the Rouge Black. I have hit a few shots that were a little longer than the 913 but overall they are pretty much equal. I did change from a 8.5 loft to a 9.5 loft. Overall I think the 915 is a better club. Also got the 915 three wood which I hit much better and longer than the 910.

Terry L.