Oldfan said:

I think a DVD-9 would make a huge difference over a DVD-5, especially if multiple soundtracks will be included.

Oh sure, with multiple soundtracks the DVD-9 makes a lot more sense. DJ's V3 was a DVD9 where the video itself was only 5.5GB and the rest was all soundtracks. That would be a good use of the DVD9 capacity--but I'm just not convinced a 7.5GB video with one soundtrack would be that much better than a 5.5GB video with one soundtrack, since they're both constrained by other more significant factors (SD, MPEG-2, DVD maximum bitrate).