Unless Xvid rips are done right... they usually end up looking sub-par. By "sub-par" I mean that you can notice the difference in framerate and textures when watching them on a DVD. I wish that the popularity of Xvid would shift to x264/h264/nero digital... those codecs produce an amazing quality-to-file size ratio and are vastly superior to Divx/Xvid. Using Nero Recode, I encoded one of my DVDs into the Nero Digital format. I set the output as 1.4 GBs. I was stunned by the quality of the video compared to Xvid/Divx files of the same size. Here's hoping people take notice to these new, amazing codecs...
XviD has an AVC codec. So leave them out. Blame DivX since because of the whole DivX certified player thing I am sure that we will see XviD ASP encodes for quite some time still. Probably the first AVC enabled standalones won't support HP either, so we will be in a situation where people are creating x264 HP encodes that don't work on SAP's or people stick with MP or even baseline for ipod compatibility. Much like XviD with qpel/GMC. You really need to look towards fansubbers, who don't care at all about SAP playback (ever seen a fansub where they cared about overscan?). Many have been creating AVC mkv's for quite awhile now. There should be no difference in framerate with an XviD avi though. 25/23.976fps in, 25/23.976fps out.