Running a FWD car so winters not quite as important for me but I've been running Pilot Sport 4s through the winter which were more than adequate, though only because they're easily one of the best non semi-slick summer tyres available on 16" wheels, the tyres I bought the car with were shocking below 5 degrees.
The PS4s are just ridiculously good now the weather is consistently going above 10 degrees, I will probably keep them on until going over to winters in October.
Strangely my colleague keeps his winters on all year round doing mainly motorway miles. He has got 40k miles out of his current set on an A5 3.0TDI Quattro.