S4 is supposed to be pretty impressive and the stability of the Quattro in the winter can't hurt. Plus the interior of the S4 is much nicer.
2014 EBII 435i xDrive M-sport
Gone: 2011 TiAg F25 X3 xDrive35i M-sport
Gone: 2008 TiAg w/Coral Red E88 135i Cab M-sport