I just got a set of YK520s for my speed3. I think I am having buyers regret. They are quieter than the stock bridgestones, but the rolling resistance feels higher (going to be lower gas mileage I am sure) and the handling feels A LOT worse. The stock tires were point and shoot, these squirm around. Not nearly precise entering and exiting corners. Feel decently planted through the corners.
So I have learned. I should have got snow tires and wheels last November instead of racking up 8K more miles on the awesome summer tires that came with the car. Plus I had to garage it whenever we got snow.
Now I won't have real winter tires for next year (YK520s are "all season") and will have to live with the crappy handling until these die....(puke)