I've determined that, even though my Def. Col. is a "better" transfer, it has too many glitches and such when compared to my "Faces" set. Alas, my Def. Col. is also missing a few seconds of Leia as well. What I'm about to determine is if the Def. Col. has a better PCM soundtrack as well (there do appear to be some differences, though not in actual dialogue.) If so, then my DVD's will have a combination of Faces video and Def. Col. audio. The commentaries on the ESB disc aren't recorded very well either (big sporadic volume jumps), but Vegas is able to tame them and level out the volume for me (threshold settings.)
My DVD's have both the regular soundtrack and the Def. Col. commentaries, with a submenu to access each one specifically. I've also come across the MainConcept MPEG encoder, which though similar to that in Sony Vegas (which I've used up until now), has more options (determining I frames on scene changes, etc.) It also has more documentation for all of the settings as well.