"And over on A Voyage to Arcturus, Jay Manifold has written further about nook-ley-ah rockets and resultant fast transit times to Mars. I could handle a 9 1/2 week trip time."

If you could use "the transportor" to beam onto a NEO and then beam off the rock once you got to Mars this "might work".
:)
Problem is he is suggesting using Ion rockets, which do have very high ISP, but they also have low thrust. To make a Ion rocket have high thrust it will require a tremendous amount of electric energy (more energy than could be realistically expected from a nuclear reactor).
I can't say I've been following the discussion, if "the plan" is to use beamed energy I might accept the possiblity.
Of course, the next problem is slowing down at Mars....