Hello - 

You are right on the money that the 910 D3 should produce a higher ball speed across a larger portion of the face compared to the 909 D3.  The 910 D3 will also produce a slightly higher launch with less spin than the 909 D3.  The club head for the 910 is 445cc vs. 440cc on the 909.  The Center of Gravity on the 910 D3 is lower and farther off the face compared to the 909 D3.  This creates a more stable head through impact and the added adjustability feature allows a player to find the optimal launch angle and ball flight.

Thanks for the answer Nick. 

Do you have numbers to associate with your explanation? Like how many degrees (or fraction) higher launch and how many RPMs less?

Math

dont focuse on the numbers so much. let the fitter do that. Titleist could publish spin and angle numbers but thats only from a machine. your swing wont match that machine and you shouldnt base a decision from that. Go to a Titleist fitting works let them put you on launch monitors with diffrent shafts and heads and let them give you the spin and angle numbers. couse the numbers the fitting works will give you is more important to your swing than what titlest gets from there machine club test. thats just me and thats why i am an advocite for club fitting.

Thanks John,

I know that this would be the best way to make sure that I have the right setup but I am in a pretty particular situation. #1, I'm lefty and I live in Canada which means that for now, there are no 910D3 head availlable to try, even the regional Rep has none. #2 I'm playing on my university's golf team which means that I have acces to some really interesting discounts. The downside is that it takes forever for the clubs to arrive. This basically means that I have to place the order right now (without having the opportunity to hit the clubs) so that I can have the clubs in time for March up come our first tourny.

Honestly, I was just curious to see the difference on paper between the older D3 and the newer one. I'm sure that the clubs I'll order (already ordered one to be sure) are going to fit me well as I've already did plenty of research for the shafts I'll play (PX 7B3 for colder temperature and 7A3 for the rest).

Thanks for your input

Math 

Good luck Math. Like in most discusions its always the little things like that. They always get left out of the initial post and leaves room for wide open coments like mine. But Its great for you that you have such a good ability to know what shafts you'll probably need and it sounds like your pretty compeitent about your needs and desires. Im sure you've reed many discussions on here and seen how vage some quistions are. I do know your pain thow. I live in Japan. Not only is hard to find a Titleist fitter but most japanese facilities don't even cary and X-flex in any brand of shaft for any brand of club. Not to mention the mark up in price couse its an imported product.  I have to find a trusted american i know here that basically uses his Knowlage as a PGA certified teaching pro abilities to best fit me. I've known him for 4 years now and hes worked on and off with me enuff to know my swing to make a well informed guess as to whats best for me. Right now were trying to decided on the Dinama white 83 x-stiff or the rombax 7x07 x-stiff with and 8.5 head. but with out having the shafts for demo its so hard to do. But hey man Good luck in your up coming season with the golf team your on. I wish i was good enuff to make a college team.  even thow im an american and love makeing the canada jokes i love you guys and i wish you the best man. Canada is a beutiful country and i've meet alot of nice people there i've been to Cold Lake canada 2 twice during my time in the service so far. Good luck finding the D3 for you man and post something in the future let me know how things are working for you.

Simba