www.ubuntuguide.org and marillat reposit

[Evan Monroig]

Hi,

I think that you all know both the ubuntu linux starting guide, and
the marillat deposit (for mplayer, codecs, etc.)

In the guide, the recommended deposits include the following:

deb ftp://ftp.nerim.net/debian-marillat stable main
deb ftp://ftp.nerim.net/debian-marillat testing main
deb ftp://ftp.nerim.net/debian-marillat unstable main

Is is really a good idea to have at the same time the stable, testing
and unstable reposits? Which one should we use with Hoary?
Why does apt-get recognise the packages from testing as more recent
than the unstable ones?

Thanks,

Evan