I will steer clear of the ogg quality debate for now except to say that if more encoders offer it as a choice then more people will use it and it will become better.

What I really wanted to say is that I use open source tools for all of my production work and I couldn't be happier. The quality of my work suffers at times, but not because the tools are lacking it's just because I spent the time to get all I can out of them. For example, my x264 encoded videos look way better now than they used to since I did some fine tuning on my encoding options. Now I have to go back and tune my options for my other formats.

Have a look at these two podcasts all done entirely with open source tools.

http://www.thesourceshow.org
http://www.opennewsshow.org

I had a nano that I won at a conference. That gave out after about a year or so and I got a Cowon D2. I like it a lot more. It plays mp3 and ogg and video. All on on a really nice touch screen. It also has an external SD memory slot. Works the same in Linux and Windows. I don't know about Mac, but most Cowon devices work with Mac as well.