I took the OP to intend a comparison between the original R11 and the Titleist 910D 2
The R11S and RBZ are different drivers.
If I remember, many people did not like the stock shaft of the R11 or its overall feel. But they did like the adjustability.
I heard more great things about the 910D2 than the R11 - the Titleist system of adjustability seems superior as well as the feel, and from comments, the 910D2 is more forgiving.