But it has been said that Meyer supervised the opening of the matte, and the framing for the 2nd dvd (it is different).
The (letterboxed) 1st DVD is shifted upwards, for Klingon subtitles. Which looks *really* weird. And it plays as horizontally squished, for me (slightly). IMDB says they're both 2.35:1, but that's horsepiles - compare them to the movies that are...
ST VI and X were the only ones shot in Super 35 - which is matted off for theatrical, and leaves a *lot* more vertical, for home-video/dvd/HD.
Super 35 is non-anamorphic - the optical soundtrack is left off, so that there is more room for picture width. I would imagine, then, that its significantly wider than fullscreen. It's useful for extensive CGI, for some reason. The drawbacks are that it has no sound in the dailies, progress screenings for big wigs require a soundtrack be added, it demands a very fine-grain film and meticulous quality-control.