Both of these cars have underwhelming performance and need a lot of tuning, but after tuning the C63 AMG is a fun sedan. Also why the hell is that '02 SL 55 AMG the only premium one of that class? The newest SL 65 AMG should have been premium.
On a side note, I was shocked to see that you can add a turbo to the C63 AMG. This puts it above some of its competition (BMW M3 Sedan which needs to be in the game, Lexus IS-F). 880+ HP sedan... sheesh.