I am using the Proxes 4s on one of my Alfa Romeo Milanos and have been quite happy with them.
BUT - we should be very clear as to what these tires are. They are labeled as an all season tire, but just barely. They share the same carcass as the T1-R Max Performance tire, with a different tread pattern and compound. The tread pattern has good water evacuation provisions but very little siping, so snow and ice traction is pretty limited.
As a performance tire, they are very good for an all-season. In fact, you probably couldn't tell the difference between the Proxes 4 and the T1-S or T1-R until you were driving above 8/10ths.
Joe