I went from the 910D3 to the 915D2 and the accuracy improved tremendously.  That bigger sweet spot made those mishits stay in the fairway a little more often.  My buddy played the 913D3 and he and I hit our D3s similar and he eventually went to the 915D2 because of the forgiveness.  Neither of us lost any yardage.  Maybe a little workability of the ball.  It is a very good club.  When you are playing badly, nothing is going to help, but it is more forgiving.  That swing monster takes over and he always wins....ha..ha...  Cheers, Chuck

I've gone back and forth over the years between models of the D3 and D3, I've probably switched back and forth 4 or 5 times. I have a really good connection with a guy that will switch things out for me basically at no cost... 

That being said, my latest change was about a month ago from the D3 back to the D2, I also changed shafts from the Diamana S to the Rogue Silver. The D3 can get kind of squirrely, although I love the smaller head of the driver it is not a point and shoot driver. I have considerably more "straight" drives with the D2 and really like the combination I have right now. I'm hitting just as far or even further right now. 

I go back and forth between clubs all the time, always titleist clubs. I have the MB's just upgraded from 714 to 716 and always tinker with the AP2, CB and might try the T MB in the full set but I always go back to the blades because anytime I switch I realize changing irons really doesn't help my score all that much even though a club might be way more forgiving and focussing on hitting the blades forces me to concentrate on my shots. I play better with blades and I score better as well. 

But the driver is different, I score and play better and play more consistent with the D2, 

Have I confused you? Good luck :)

T

During fitting I tried both but in the end decided for the D2, as it was more accurate

I have both and go back and forth. I think I hit the D3 farther, but more room for error with the D2.