I have ridden a set of SRM cranks on Rotor 3d+ CRANKS since april.
Seems just as stiff as my former Dura ace 7800 cranks, and really not much to say than it works really well
As long as you DON't use a frame with BB80 (or similar) press fit BB, The Rotor cranks can be used on both BSA, BB30 and BBright frames. I am on a old style BSA frame, and the special Rotor bearings works really well for this
EDIT:Sorry looks like I was wrong here. Rotor 3D+ should also be compatible with press fit BB80 frames. Press fit bearings are actually listed on Rotor's homepage.
Well, then I guess I would choose the Rotor over BOR: The weight of the Rotor is quite a bit lighter...