I owned the 913 and never had good results with the club.  I ended up going back to my old driver which was a CW BB b/c my game was suffering off the tee with the 913 (just being honest).  But being loyal to Titleist, I had to give the 915 a try.  The driver is the only non-Titleist club.

Titleist was holding a trial event at a local course and this was finally my chance to test the 915 driver.  I tested the 9.5 and 10.5 D2 head w/ Mitsubishi Diamana S+ Blue 60 and Mitsubishi Diamana M+ Red 50.   They were using the Trackman on each club i was testing and even recorded the numbers from CW to compare.  

Best results:  D2 10.5 w/ Mitsubishi Diamana M+ Red 50 (almost similar to CW setup).   

My thoughts:  Very impressed with the 915.  Not only were the numbers better but when I didn't hit the center of the club, my ball was not far off from my target.  I just couldn't believe the forgiveness I was getting.  My current CW did not provide that type of forgiveness. 

Conclusion: I would buy this club base on the forgiveness.  I've never been a long ball hitter and to be honest I would much rather have the accuracy over distance.  

I really can't comment on the sound since i'm hard of hearing.  Sorry.

I need to start saving....