Remasters of mono soundtracks into 5.1 sound can often cause serious problems. Sure, if you have the resources of Paramont at your disposal, you can come up with something like the Star Trek original series DVD's, but for a small outfit like Voyager a 5.1 remaster would wind up sounding horrible.
Secondly, the original theatrical ratio of the Yamato movies was in fact, 4:3 (aside from "Be Forever," which switches to a widescreen aspect ratio mid-feature, something which VEI preserved). Add to this fact that "New Voyage" was a TV special. I would much rather see the entire picture, as upposed to someone cropping it into false widscreen.
That said, this is a great movie marred by Voyager's lackluster presentation, and (non)preservation of their masters. Between the release of the VHS version and the DVD, the masters have actually disintegrated so that the main feature has TAPE FLAWS!! At one point it looks like you're watching a tape that's being eaten by your VCR.
If you have the VHS version and it's not disintegrating, don't bother with this disk because your tape is actually a better presentation. The extras do not make up for the damage to the main feature.