There has been a great deal of negative hysteria surrounding the new Impala, with hyperbolic criticism from many, including myself. However, given some time to look at it, I think this is unfair. In every respect this car is a definate contender beyond any other midsize GM car. Here's some comparison to its main competitors - the Camry and Accord.
Base: 2.4l 4cyl 160hp 163lb/ft
Mid-Range: 3.0 L V6 210HP 220lb/ft
Top: 3.3L V6 225hp 240lb ft
Transmission: 5-Speed manual w. Available 5-Speed auto in base models, standard 5-Speed in V6 models.
Base: 4-cyl 160 hp 161lb/ft
Mid-Range: 240hp 212lb/ft
Top: 240hp 212lb/ft
5-speed maunal or 5-speed auto
Base: 3.5l 210hp 220lb/ft
Mid-Range: 3.9l 240hp 360lb/ft(?)
Top: 5.3 V8 303hp 323lb/ft
Conclusion: I think this new car compares much better, epsecially on interior, than either the old Impala or the other W-bodies. Its now ahead on engines. If one assumes that the price range remains similar, a 3.5 Impala should be equivilant to the 4-cyl Accord and Camry, while the 3.9 beats both the competitors midrange, and the 5.3 has no comparison.
I think this comparison is much more important than the comparison to the 300C. Inspite of that cars success, it did not sell as well as these Japanese offerings. These are the cars to beat, and Impala no longer embarasses itself to the point of needing big rebates to move.
BTW: MUCH better pics of Impala are at Chevy.com.