My pick in this one would be the Cadillac all day long. Johnny Lieberman disagrees, though, in favor of the Merc for some very subjective reasons. That’s the name of the auto journalist game, though. But for me, the Caddy’s more nimble handling, better performance measures, and $15,000 savings make it the obvious choice here.
Having said that, between the BMW M3, Cadillac ATS-V, and the Mercedes-AMG C63 S, there is no bad choice at this point. These are all phenomenal cars.