Well, my position is that everything works fine and for my purposes the only advances are marginal so I can stay where I am. Even though I have installed various flavours of 13 or 14 on friends' computers when they complained that Vista or 7 was making their computers so syrupy that they were thinking of dumping the whole computer. (then they were all ecstatic about how blazingly fast they computers run, as we all know). Frankly I cant see the difference in computer performance
between the releases, which isnt the case with the need to get the newest OSs as they are released on my Macs.
The problem is that no one can identify the problem OP had "W: GPG error: http://archive.ubuntu.com oneiric-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5
" and I always get nervous when this happens. Even if I can figure out a (manual) workaround.
So I am wondering: All I have on the computer is my browsing history in FF & Chromium (and a record of the 20 open tabs I keep in both!), some customizations which probably aren't relevant any more if I move to a different flavour, some downloads which I can easily cut-and-paste to a flash memory drive and a few installed apps I got from package repositories.
This is actually quite a difficult one!