Ford have convinced me too, that their two listed cars here are not the best in their class.
Crown Vic vs. 300C and LeSabre. Clearly the LeSabre is the worst in the class, has the image of a geriatric 80 year old man and the performance to match, although Buick now builds extremely reliable cars. But the 300C easily takes this class, performance, luxury, and practicality all in one package.
500 vs. Impala, Avalon, Maxima, and GP is a bit more tricky. Money aside, the Maxima easily takes this class with performance, practicality, and Nissan build quality. As for a cheaper option, the Impala pwns the 500, since I know some people who own them, and they are great cars by all accounts. It's also surprisingly good on fuel! As for the Avalon and GP, I don't see too many of these on the road compared to the Maxima and Impala, so I don't think many people are missing out on something too special here.
But as far as the 500 goes, I think it is the most bland, generic car ever. It is the most bland car I have ever seen in terms of styling as far as the last 10 years. As for the rest of the car, it appears to be very, well, average for it's class. The only thing that appears to set it apart from it's class is cargo space. Ford claims it can hold 8 golf bags in it's trunk, which is not a small feat.
But, I'll wait until some reviews of this car come in before I formulate an opinion, these are just first impressions I have.