My understanding is that these 'length of stay' deals don't get you a great deal on the pass but do get you a slightly better deal on the room.
However, if you are using the Entertainment rate, you're probably better off buying your tix separately. there's a 3rd day free deal on now.
Why not just call and do some comparison shopping. Loews number is 800-23-LOEWS. Universal Orlando Vacations is 800-711-0800.