Vista RC1 installation question

Hi - I had been running Vista Beta 2 Build 5384 as a general beta tester. I
found a few bugs and reported them. But because Build 5384 ran slowly, I
removed it.

It's my understanding that subsequent Builds have solved many of the speed
problems, but those builds are available to general beta testers.

Question: When RC1 is released, will I have to reinstall Build 5384, or
will I be able to install RC1 as a clean install?

I still have the Build 5384 Product Key.

Thanks

Joe