I know all season isn't actually all season. I had summer and winter tires on my Jettas. But I have to say, in all the conditions I've driven in, these tires have been fine. Yea, when the road is covered in snow I need to slow down a lot, but I would anyway. They're Conti Pro Contact, and I had them filled with nitrogen before the winter. I think in 6,000 miles of driving we had one or two very minor fishtails, and one instance where I didn't know if we were going to stop--but that was an ice issue and will happen with any tire.
I live in south eastern CT, so to put snow tires on doesn't make sense. We get enough snow to warrant snow tires once or twice a year.
If I moved out west, or up north, I'd get them for sure.