Hi Rick,

Swingweights will vary dependng on the shaft, but the swingweight for a 915 with a Rogue Black 60 or 70 at standard length with a stock grip should be D2.

Cathi, my 915 D2 is currently D7. Any advantage to moving it to D2 or D3?

Hi, The advantage would only be if you can swing it faster and center face it more often. One of the things we have found is if a player can swing a slightly (1-2) higher swingweight without losing speed, they will gain in performance. Our new 917's are 1-2 swingweights higher than the 915 (although with our CG weights, you can request a lower or higher swingweight when ordering your club).
That being said, D7 is a fairly high swingweight - mostly used by higher swingspeed players that use the swingweight to feel the head during the swing or players that have a quick transition.