Living in Seattle, and I can tell you it's amazing. I've been driven on almost bald rear tires in winter and early spring... couple minor incidents coupling oil slick and crosswalk markings (some drifting which is fun when I didn't hit anything nor spun, well my wife's lecture is a different story though)
yes, I never felt the pulling in the puddle sensation as my other car does.
Yes, you need full tread tires.
Please, go sign up for a HPDE or even autoX days, preferably in Rain, for once. Then you know exactly how it drives in rain.