For purposes of sovereignty and border control, an EEA membership is an EU membership without the right to vote. You don't leave the EU only to stay in the EEA. The EEA is deliberately bad in order to push the member countries in the direction of an EU membership. For Norway, an EU membership wouldn't really offer much of a benefit, though. There's not much Norway can do if the big countries push a piece of legislation. Britain has far more influence as an EU country, for example.