I agree, absolutely amazed about the performance of my X1 in 30cm + of snow this last week. I have normal all weather 225/50/17 tyres on my XDrive and have not had any hint of a problem on powder, slush or ice.
Seriously, stunned to say the least. Oh and I also live up a very steep hill.
I think the only thing that would stop my X1 in the snow is if its too deep and you start ploughing.
PS: Don't have a pic with the X1 in it but these were the conditions at the house yesterday !