The new Alfa Quadrifoglio has an estate version coming out on the not too distant future. I drove a test mule around Millbrook and it was very nice indeed. A bit of a harder ride than the RS6 (I'm on air), the adaptive damper settings went from super hard to mildly jiggly. Cabin was less plush than the Audi with a few naff plastics but in no way was it a nasty place to be.
In general the driving dynamics were better with a lot more feel coming back through your seat and steering wheel. The brakes were very, very impressive.
The new Stelvio is coming out as well, will carry the same engine and early reports say it'll be best in class.
I'm half thinking of ditching the RS6 before all the 3 years finance boys come out of their deals and getting the Quadrifoglio. Alfa treated me like an actual customer. Audi treat me like sausage number 436 in the sausage factory, I've had 4 major faults in 12 months (geo out by a mile upon delivery, brakes & pads replaced after 3k miles, electric folding mirror croaked twice) and I don't like it. Perhaps I just have a Friday car
I couldn't settle with the c63 and live in the wet part of the country so prefer a bit more traction.
Here's my list of potentials:
Tesla P100D (range anxiety issues)
Alfa Guilia Quadrifoglio
Stelvio QV (assuming it's dynamically up to the job)
Panamera
I-Pace
The other side says just hang on to 2017-18 for a boat load of new EV's from the big manufacturers.