Michelin Pilot Sport a/s vs ss

Z Bear

I live in the Northwest Seattle area and my wife drives our '10 370z coupe w/sport pkg. Our odometer is turning 19k and its time to replace the stock Bridgestone Potenza 050a's. If it's snow or ice, she takes our 4w truck to work (20mi roundtrip). Our winters can be very wet and if she happens to get caught in some bad weather, I thought it might be best to try some all seasons. The Michelin Pilot Sport A/S seem to get fairly good reviews but has anyone here actually run them on their Z with the sport pkg ? Also, is it true that tread wear ratings can only be compared to tires by a specific manufacture ? For example, a tread ware rating of 300 by one manufacture would not necessarly be the same as another manufacture ? Just looking at the two tread designs between the A/S and SS, one would think the A/S would displace water much better than the SS ? Please, any more comments on the Pilot A/S vs SS would be greatly appreciated. Thanks for all the inputs, Z Bear