It looks like this firmware fixed an issue I had with one of my 4GB SD cards! With older firmware the card data always got corrupted after a (short) while, but now since the upgrade it has been working great since. (The corruption happened with the modified SDHC kernel too.)

Other than that the upgrade was pretty painless: Mainly because now the backup can restore even the repositories, which before took most of the time to find url's and type in...

Also in general the N800 feels "snappier" than before.

All in all I'm happy!