Leo says to get the Sharp if it's only been there for a few weeks and the warranty is the same. However, Leo does like the Vizio. It would give him a lot of quality for the money.
Open box items like this are typically just bought and returned, and the law says they can't be sold as new. He should make sure that was the scenario, and that it wasn't refurbished by the store. Leo would be careful about anything that wasn't refurbished by the actual manufacturer. It's also important to verify that it's the current model Sharp TV and not the one from last year.