It depends. All season tires are actually really good in the kinds of conditions we get around here in the winter - cool to cold with wet or damp roads. We're talking from freezing up to 50 degrees or so, lots of fog and rain/drizzle (SF Bay area). In these conditions, summer tires (particularly high performance ones) may not get up to their designed operating temperatures and the grip can be much lower than drivers expect. And I've never found a good set of winter tires that does well on wet roads.My advice? Stay away from No-season tires!
If you HAVE to get No seasons, since they are not designed well for any season, at least get H rated tires with some properly stiff sidewalls to every little gust of wind doesn't make you feel tipsy like the crappy T rated tires do that came with my vehicle new. Then I'm going to pick up summer rims+summer tires, and I'll use my OEM rims for winters tires.
YMMV - but all tires are a set of compromises - you just have to find the ones that work best for you. For me, a set of good high performance all season tires work out very well - good enough for summer driving, and much better than summer tires the rest of the year. I haven't tried the Contis, but the Bridgestone 960 Pole Positions were great in the OEM size for my Acura TSX.