Clean Install
Doing an Clean Install with ANY OS is always better. Just make sure you have the install media and activation codes for all of your installed programs. If you 'Upgrade', you may have corrupted .dll files that could cause problems, OEM crapware that will make your system run slow, Spyware or Viruses. Get rid of all that old crap! A clean install is always the best way to go. In fact, I regularly reformat my hard drive and do a clean install every few months. I reformatted it twice today.