I honestly think this was the right call. A have your cake and eat it, too, scenario. Live somewhere warm, or have a Canadian summer where AWD isn't "necessary"?
Rainy day? A touch of snow? Pure track fun?
The funny thing in my mind is that the RS7 doesn't come across as a funtzy schmuntzy 6-figure beast. The M5 has always, in my mind, been a halo car. It may look like a regular 5-series, but those who understand proper "M" cars know that the M5 has always been a wicked ride.
...and now it's wicked quick.
I'd lease one if I had the means. Now with AWD available, maybe it'll be FIL's next. Who knows - it's why he got the Ghibli instead of considering the Bimmer - RWD is a no-go in his mind.