This isn't quite accurate - Panavision and Super 35 use the same basic 35mm film, but generate the image differently. Anamorphic widescreen processes such as Panavision utilize the full frame (1.37:1) of 35mm film, with the anamorphic lens squeezing the 2.35:1 image to fit the 1.37:1 frame. As you pointed out, Super 35 hard mattes the same basic cell down, rather than using the anamorphic lens to stretch the image out. In the latter process, you're using less film area for the image, which automatically limits the resolution, no matter what kind of lenses you're using.Technical details. Star Trek VI was indeed shot on a higher quality film called Super 35. It's designed to be matted to a 2.35:1 aspect ratio for cinemas, and completely opened up for home video release. Films shot on Super 35 have slightly less detail in the cinema presentation compared to traditionally shot Star Trek movies, but it is made up for with it's inherent sharpness, and much higher depth of focus.
The reason Super 35 was created was never for home video, though it ended up being repurposed for it during the pan-and-scan days. Super 35 was created as a way to make a widescreen image cheaper, without needing the expensive anamorphic lenses, which could take up additional space in tight spaces. Tony Scott used this space-saving bonus to his advantage when he was shooting the cockpit scenes in Top Gun.