Originally Posted by Powerslide
Np - S4/S5 for open roads, D4 for stop and go rush hour traffic (why I love DCT). D4 is what allows you that sudden ability to take advantage of a passing opportunity as well - the car will automatically shift down the number of gears commensurate with how much pedal you apply - you can get just enough power without having to rev high and call attention to yourself - or gun it if you feel like it or need to.
Granted - as effortless as a C63? Of course not. Sufficient torque at the wheels for DD purposes? Definitely. All other factors being equal, would I like even more torque? Of course I would - who wouldn't? Despite the foregoing, any regrets having the M3 as DD instead of C63? No (again though, I'm sure I would love driving the C63 as well - I just happen to like the M3 more)...
S5 only for me. I don't think I've ever tried a D mode.