SABR heavy was going to be CH53 which is fully folding and is perfect, just ask the USMC.
No, they're not. The H-53's the USMC currently has are rattletraps.
Furthermore, The tandem rotor or coaxial main rotor design is better than single main rotor and tail rotor for the heavier lift/transport role.
Instead of building H-53K's, the DoD should be requesting wider, upgraded Chinooks, with Navy, powered folding rotor versions of same available.
I am diplomatically avoiding any comments on the hover payload fraction of the British Merlin.
... Several of the previous posts err in assuming that:
(a) Any helo in operation now will be desirable fifteen or so years from now;
(b) Fifteen or so years from now has much relevance to operations in Afghanland NOW. At times, the future is now.