Well, actually, have you used either OS before?
I've used RSX professionally some, and it's basically like VMS anyway :)
(Note the smiley, Johnny!) It's not too hard to adjust, especially if you
set your CLI to DCL (although I'd consider that cheating).
Never got paid to use RSTS for anything, and I have very little experience
with it. But that just means it's an opportunity to learn...
Actually I don't know how well either OS will do at supporting
"non-standard" devices on the SQ739, like CDROMs or Exabytes. In theory
MSCP is MSCP, but in practice it's often not that simple.
Also I don't know how fast (or how slow) either OS would be on an 11/53.
It's not a slow CPU (it's basically the same as a 11/73) but it's not the
fastest either.
Bob