I put in that disclaimer because some people have well functioning systems using
a previous version of Ubuntu and have found that 8.04 was not as good for them.
There is no need to upgrade, if you are happy or if the Live CD does not work on
your equipment as well as a previous version. I have been using 8.04 since
before the beta and it has not let me down (except perhaps with the alpha and
KDE 4, but Gnome and KDE 3 have always worked for me).

With so much positive press, I don't want users to feel pressured to upgrade
just for the sake of it and then experience problems that could have been
avoided if they left their system alone. I am glad that it works for you as well
as it does for me.