IME, it applies to any prior version, beta, RC, CTP, whatever.
The RTM DVD will start up, then identify if you need to follow the uninstall
instructions (providing a link to the instructions). I recommend you do
exactly as instructed. On one PC I did what I'm recommending and all is
well. On a second PC where I'd uninstalled the RC myself (probably in the
wrong order), the RTM keeps finding leftover bits I can't seem to get rid
of. I'm now in the process of trying to reinstall the RC so I can uninstall
it according to the instructions.

Sorry, I've been away all day.

I've run into this problem before. What I did was to uninstall the new
version, perform all the tasks required to remove the old version, and then
reinstall the new version. Of course, I've been doing this every couple of
months for about a year, so I can't remember whether I ever had to reinstall
and then uninstall the old version at any time.

Once you follow the directions exactly, it should perform very very well. It
has for me, on 2 different machines. I should also mention that I'm still
using the RC at this point.