I've seen several replies from Titleist to other TT members asking the same question and the answer is yes the sure-fit adapters are interchangeable between the 913 and 915.  If you have 913 FWs or Hybrids, those shafts with their sure-fit adapters can also be used on a 915 head.

I currently have all the 913 with the Diamana 72 White.  What would the closest shaft on the 915 options?

Tate

I would recommend trying the Diamana D+ White 70.

I have a 913 D3 with the Diamana White D+ 72. 

I had the pleasure of getting to play a round with the 915 yesterday. Very nice driver head! Yes, the sound is different and takes some getting used to but didn't take long and it;s not as loud as many of the drivers out there. I like it a lot.

However, I tried the Diamana White D+ 70 along with it and it felt VERY different. I ended up putting my 913 shaft in the 915 head so that I could get a better feel for the change in the head only and it felt much better. I'm confident that the 70 shaft isn't right for me even though I very much like the 72.

I'm doing a fitting day on Saturday and plan on comparing the 72 to the 70 again as well as the Aldila Rogue and any other shaft the fitter recommends. I'd be happy to report back my results.

One thing I did notice is that the ball seems to stay a bit lower on the 915, which I am happy about. Could be me, but that's what I noticed as I generally hit the ball high.

[My current setup is 913 D3 8.5*, D+ 72 X, D-2 setting, avg drive 300]

[Setup I tried was 915 D3 8.5*, D+ 70 X, D-2 setting --as well as the above shaft on the 915]

I may try the 9.5* head on Saturday and see how I like it.

I just got the 915 d3 with the 70 diamana i did have the 72 diamana in my 913 got to say i am hating this 70 it feels like a reg shaft dead whippy and i have sold my 913 gutted...just wondering what you think about the 70 shaft

went to a Titleist day 2 weeks ago.  The Rogue 70 stiff was much closer, and i felt, better than the Diamana shaft from my 913.  I'd try that shaft.