Reading Topic: Mazdaspeed Protege?
It really depends on what you are looking for. The MS Protege is not set up to be a commuter's car and it was definitely not designed to be luxurious. It is a quick corner-carver that requires a driver that is willing to push it to its limits and then some. In stock forms, it will nearly keep up with a 6s and easily out-handle the 6. Its turbo set-up was deliberately tuned for linear power and to feel like a small V6 rather than a high-strung 4 so that cornering would not be upset by a sudden rush of power. Also, the limited-slip in the MS Protege allows you to power out of corners rather than going through the wheel-hop that is inherent of FWD in that situation. The MS Protege also gets better fuel mileage, a better sound system, and all of the boy-racer looks. Getting all of this in a warranty-backed package for this price is hard to beat.
That said, if you want a car that is smoother, quieter, and generally more refined, the 6 is your best choice. The 6s is slightly quicker in a straight line but will fall back in the twisties. Also, the 6 has cruise control and the availability of a moonroof, both of which a MSP Protege cannot have.
If this car will be an everyday driver and you spend a lot of time in it, the 6 is your best choice. If you want the looks, handling, and sound system without having to spend extra money with aftermarket mods that may or may not void your warranty, the MS Protege is the best choice.
Your best bet is to go on a long test drive in both cars. They are so different; you'll know which one you prefer.