Interesting, I had thought that they were the same. Who created OGM? Someone totally unrelated to Xiph? (the wikipedia page doesn't say)
I'm using Handbrake because it produces by far the best results (auto cropping, optional noise reduction and other filters, multiple audio tracks, chapter marks, etc) from anywhere (disc, iso, DV, file, etc) with a tiny amount of setup work on my part. Good queue management, etc. Is there any equivalent for Ogg?
Transcoding is a wasteland of half-finished, horrible projects. I feel lucky to have found Handbrake.