So I took a good look at the files and I had an xvid at 704×400 (I cropped a little) and an ogg theora with 720×480 resolution. Generally speaking, the ogg theora had much better audio/video sync. Throughout the entire film, the audio was just as in sync as on the DVD. The xvid file lost sync little by little, but never to a ridiculous degree. (Although it has happened to me with other discs)
However, I found the xvid to show less compression artifacts at full screen. However, the video fidelity was just barely better. In fact, whenever I have the time before a trip I always encode in ogg theora.
So, in [this long delayed] conclusion, I say OGG is the best if you want good audio/video sync, and want to support Xiph. Xvid is good if you want others to be able to watch it too. The worst part about Thoggen is how ridiculously slow the encoder is, but I think work is being done on this and it should be fixed relatively soon.