Mostly I was concerned about 704x480, from the point-of-view of compatibility. Yeah, it's a valid part of the spec, and I use HCEnc so creating a valid file isn't the problem, but do players actually do the right thing with it? I've seen a number of reports about hardware players that make me a little nervous about using this lesser-known DVD resolution. Also, I'm a little fuzzy on the benefit of nominal analogue blanking--is the lack of blanking on this resolution an issue? But mostly--why do the places that actually bother to have the correct aspect ratio always seem to opt for 720x480 with blanking? That is the question that really makes me concerned about the player compatibility of 704x480 video.

As for 720x480, so many players already get the PAR wrong, and it doesn't seem like any newly-created players are doing it right--I'm seriously wondering at this point if I should just forget the specs and encode at 720x480, just anticipating that the player will get the PAR wrong and by virtue of two wrongs making a right, the image will look correct. That is, apparently, the path most major studios are taking.