If you have System Restore enabled, a restorepoint is created in any case during installation. I created an additional one before starting anything, just to be sure. The add/remove option is basically a different thing. If you are not too limited in diskspace (about 220MB needed) take this option too. If you for instance decide to remove it in 6 weeks, you will loose any changes you made during this time if you use System Restore. Further it is not sure if you still have an pre-SP restorepoint then. It depends on diskspace allocated to Systemrestore and on how many new rest.points you create.
If everything works fine and you need the space, you can remove the backups at any time. So I would recommend the save way.