To a certain degree it already is configurable on a per-user basis, right? Your upvotes are "saved" for you. The only other user-configurable option would be to

To a certain degree it already is configurable on a per-user basis, right? Your upvotes are "saved" for you. The only other user-configurable option would be to "hide" items that you have voted on or manually hidden (a la reddit). Does that require more server power? Sure but not 2x, right?