Does what it says on the tin. Seems to be the only unloading extension out there that does it on a timer.
Would like an option to disable the recently-added favicon replacing though - the pink blotches are unsightly and, for those who already have styling set up around unloaded tabs, unnecessary. The extension also fails to retrieve favicons of unloaded tabs after a browser restart / session restore, so you end up with a bunch of "default" icons with pink circles on them.
Would also be nice if it integrated with Tree Style Tab, so its menu options show up on the side tabs as well.