Ts2 with smoke shaft will do the trick

It is laughable to universally suggest the Smoke shaft or any other shaft for that matter, because what works for you does not necessarily work for him.

When hitting the driver, which bums golfers out the most - a bombed drive with an ugly curve or a moderately straight drive with moderate distance? I thought so. Because of this I don't pay too much attention to spin rate in the hitting bay because you cannot measure spin rate on the course so why fixate on that parameter?

To the original poster, if you like the shaft in your 915, simply put it in the TS as a starting point but I caution you three ways. (1) A shaft in one clubhead will not behave the same in another clubhead, unless the weights of both clubheads are identical. (2) As your body ages you will not be able to load the club like you did when you were younger, which could be grounds for a shaft change. (3) A good player can swing several shafts with similar dispersion patterns (ignoring the distance and trajectory) so be cautious of a potentially unnecessary expensive shaft upgrade versus what Titleist sells in the driver.

Go to a hitting bay with a launch monitor and watch two parameters - dispersion pattern and spin rate. Expert club fitters can interpret all of the other parameters to finite relevance, but judging from your wording, there is not a specific problem you want to address.

For many years I played the Graphite Design Quattro Tech MD-7 shaft, switching it from the 910 to 913 to 915 to 917 to 913. That shaft has been feeling "boardy" to me as my swing speed has slowed from 107 MPH to 102 MPH. I have a Fujikura Speeder VC 7.1 and an Aldila Proto VS as well. The Speeder is a bit to "springy" for me, so right now I have the Proto in my driver because it feels great to me, and has the tightest dispersion pattern of these three shafts.

The summary here is, unless you can self-diagnose your swing and have access to dozens of shafts to try, you may be better off with the factory shaft in the driver and fairway. If you are adamant about changing shafts, see a fitter. You may be surprised to be recommended a shaft other than the Project X.

Best advice, set up a fitting with a qualified Titleist fitter (preferably outdoors) and you will be able to baseline with your current driver setup and then work from there. When I went through my TS2 fitting last fall what I found out is that the shaft I had in my 915, which I felt was a great setup for me and yes I was fit for the setup, just didn't perform the same with the TS2. It just proved to me that what we think/feel isn't always correct.

Add me to the go get fit crew. Titleist Thursday are really good because they are free and you are getting fit by titleist reps who have training from the staff at TPI. They have a variety of shafts and will get you dialed in. Everyone’s swing is different and factors like ss even if the same between two golfers could result in different shafts and head/lofts because of how the club gets delivered

Go see a Titleist certified fitter. They are the experts and they can let you try multiple shaft until you get the right set up based on the numbers off Trackman. That is the ONLY way I ever consider a new Titleist driver set up or any new equipment from Titleist. They have NEVER let me down.