I recommend full reinstall. I always do that with every computer, every OS. It's probably a smart thing to put it on usb flash drive first. It installs in 20 mins on slowest computers that way. I've got MSDN subscription so I have tested all betas, rcs and pre release.
If you are sporting around SSD and you're worried of loosing data then you're doing it all wrong
Full install is the only way to make sure it works as intended.