What did you want to know specifically?

I've been using mine since day dot when it was released, but didn't have a driver in my bag previously to compare it against.

The adjustability it offers helps a fair bit, I got it refitted yesterday and jumped from a 250m average over 10 balls to once spec up correctly 275m carry average after 4 balls.

Very happy with the feel n distance I am getting from it and the dispersion I am able to achieve is not too shabby considering I really only started playing again at start of October. Hitting off a 15 Handicap with around 110ish average swing Speed.

Hope this helps you.

I received my 917D2 driver in late October and recently used it in a tournament in Nevada. Performance off the charts. When I was fitted for the 917 I used my shaft from my 915 driver so it was strictly the head that was tested and it proved 8 to 12 yards longer. At the tournament the drivers were longer than previous years. I am waiting to get fitted for the fairway woods this spring and have no doubt that they will have some technological advantage over my old fairway wood.

Hi Jimmy,
First of all a small disclaimer, I have been a Titleist devotee for a long time. I haven't used clubs from anyone other than Titleist since the 905 was released. I have every driver and fairway since with the exception of the 907 (not sure what path they were taking with that one). I had a fitting session today for the 917 and will be going with the D2 and F2. I can't promise that the 917 is any longer than the 915 however dispersion was noticeably tighter. Sound was so much better too! If you are keen to try the 917s get along to a demo day. I'm sure you'll be pleased but I must say the full fitting experience is definitely worthwhile. Without the 2 hours with the trackman, I would have gone with a completely different setup. Thanks B.J for putting me on the right track!
Good luck,
Mark