The Taurus is nice....can't say I care for the looks overall, though...I much prefer the new Fusion...anyways,
Since you already have a Camaro -- I'd say you've got performance covered. The Buick will provide an exciting, healthy balance of performance and comfort to serve as a perfect daily-driver. It has better fuel economy, more luxurious, interior far lower price (almost 5 grand), and a host of unique features like adaptive headlights (they turn with the steering wheel), and HUD, etc.
I would go with the Buick.
EDIT: And I pretend like the Nissan doesn't exist, because....well it doesn't:
Buy American!! 