We're using entirely different definitions of sf. I'm using it to mean "science fiction"; you seem to be using it to mean "hard science fiction". I agree that neither Farscape nor Who is hard sf, or trying to be, or needs to be. But the difference between them is, as you say, internal consistency -- Farscape had it to the extent that the miniseries picked up threads from across the show's four-year run (including apparent throwaways like lines from "... Different Destinations") and wove them into a more-or-less coherent whole. It wasn't perfect, of course, but the writers clearly wanted a story with large-scale coherency. Who is never going to even try to have large-scale coherency, but on its bad days, as in "The Runaway Bride", it doesn't even try to have single-episode coherency.