Alright, tried to convert in virtualdub. Few things I noticed...
1) Vegas reports the converted clip as 23.976 fps, so that's good
2) Video quality seems degraded. I'm no expert at this, but the converted file is clearly degraded compared to green's clip - it's either duller, or more washed out, or *something*. I compared his clip to my original DVD source and they look fairly comparable, so it's something that happened in my conversion.
3) I converted as lagarith avi (which maybe caused the problem in #2?), but the file is still huge. It's 50% smaller, but should it still be 1.4 GB for 1 minute of video/audio?
4) Green's clip and my converted clip are slightly different AR from the DVD source. The height looks the same but the width is slightly cut off. Is this due to the 1.0 pixel ratio instead of the 1.2121?