I would say, however, that, IMHO, the FROP school, being more stilted and insistent upon sticking to what Uncle Whiskers himself said, slightly implies a more orthodox Marxist politics (vanguardism and power seizure as the foci), while the MR tradition, as I experience it, has tended to imply that we should be trying to build something like a New New Deal -- more global and radical and democractically governed than the FDR version, but with many of the same features.
Of course, there is another dimension to your question. Isn't it politically important for movement-building (something we all agree on) to tell as much of the truth as we can manage to tell? Doesn't that both promise to attract more folks, and to lay a better basis for the movement's course? At that level, choosing between FROP and MR is immensely important.