It's not that they're unsafe, or egregiously bad...there's just a lot of tread squirm, especially at higher speeds, so it'll feel like it wants to drift on you a bit.
I drive mostly highway miles and it's not a huge deal, but more of an annoyance. I'm considering high performance snows once these are worn, but I'm not sure I'll be happy with the trade off in deep snow performance. From what I understand high performance snow tires don't work nearly as well as more aggressive snow tires in such weather...although they're much more pleasant to drive on dry roads.
I'll put it like this: I'm none too pleased with the highway performance of these tires, however I'd probably do it again, especially if I can't find a high performance snow tire that still works well in deep snow and doesn't cost a fortune (and fits my 15" winter wheels). I drive mostly highway, but I'm on back roads enough that the aggressive tires are worth it.
Hatch Nation #29