Especially in English car magazines, they praise the current AWD M3 as an all weather unflappable tool. Judging by my experience so far that works in the dry but it gets quite exciting in the wet 😉 Not having tried the new AWD C63, I would say if you’re not a fan of twitchy behavior, in the same size the RS4 will be a lot less nervous.
Before the M we had a C43 and while the engine didn’t have the performance, it felt a lot smaller on a curvy road - I.e. allowed you to take more liberties 🤷🏻♂️