Forgive me for repeating an old story - during the mid-December deluge (i.e. the whole 'cars abandoned' ... 10 hours to get home ... roads not gritted debacle) my Q4 was fantastic... albeit with normal road tyres.
Traction was great - if you did (and I did) overdo throttle it would start to slide out to the rear very briefly - initially unnerving but it catches itself very quickly and brings itself back in line (that was both with and without VDC/ASR activated).
The highlight of this particular episode was when I got close to home. There were numerous individuals having took refuge in my local pub at the bottom of a short yet relatively steep (and ungritted road). There were some smokers and the like outside surveying the 'carnage' of abandoned motors. Next thing, they clock me turning into the road and I am absolutely certain they had a look on their faces saying 'Alfa Romeo... no chance and good luck getting up there mate'.
I gently, solidly and effortlessly trundled past them up that hill ... and all the way home (albeit after 6 hours to do 20 miles). It is something I won't forget in a long time.
Alas for different reasons, I will also not forget the numerous idiotic BMW drivers who vented their frustrations in the snow by sticking the power down, lighting up the rear wheels (presumably less controllable auto/flappy paddle variants) which had the effect of instantly polishing the snow to ice in mere seconds and making it impossible for the next car to traverse across! I saw this a number of times that evening (admittedly they weren't all beemers but you get my drift!).
As per my original post - Q4 rocks!