We had a few days of snow here in Denmark before I've replaced the SC7 with some Pilot Alpin 5s (245/35/19 all around). It was doable, but the Alpins grip a lot better.
One intersting thing about the SC7s now that I've been driving on them on track and the street - perhaps they grip a little too much? On B roads, I mostly drive with DSC OFF and I like being a monkey and sliding a little bit through corners. The SC7 can do that in 1st gear, but you have to be *really* on it, and there's a harsh snap when it corrects. As I remember, with the PSSs it was more enjoyable and they were more happy monkeying around.
I'll go for narrower rear tires next time, I don't think 285s on a stock OG M2 is needed.