Right now I'm rendering everything using the Motion JPEG codec rather than DV. It looks good. I can spot the tiniest bit of JPEG compression perhaps on the black bars ... but even that I'm not sure about. It looks nice, and it transfers to M2V well.
My test was "I love you/I know" and that is a huge improvement of course, it looked awful before. I've cracked the code now. No damn artifacts on all the reds, just lovely Empireness.
What I think I'm going to do now is render possibly the whole thing over again as motion JPEG, or the material around the carbon freezing material at the very least, pretty much the whole ending actually. Knowing me, the whole thing.
Whenever I do this again, I'm going to use any codec other than DV, as DV has just been this huge ugly mess for anything that wasn't DV to begin with. Motion JPEG I think is all right because it doesn't seem to be insanely hard drive space intensive ... but I'll learn about that now I guess.