We bought snow / winter tires for our 2014 Subaru BRZ. The old tires we had, Continental Extreme Contact DWS (All Season) were a good set of tires for commuting, road trips, etc. At five years of ownership (and tire age) we started to autocross. The additional tire wear severely reduced traction and tire performance, even in normal driving. The car got a lot more skittish.
By skittish I mean the car was a lot more prone to spinning the rear wheels and over steer. We decided that despite the fact that our old all season tires had only been stuck in winter twice, it was time to replace them.