I posted this in the tires forum as well, but just in case anyone with sway bar experience has anything to add -

I've had some Pirelli snowsport tires on the MINI for the past month or so. With this mild winter we're having I probably could have just kept the summers on, but that's another deal altogether.

I have the Alta three position sway bar, set to its most agressive setting. That setting worked great with the summer only dulnop runflats - I've noticed that while driving (spiritedly, with the DSC off) around on ramps and things, that there is now a much bigger tendency for the rear end to come around than there used to be, and this oversteering condition was definitely not present with the summer only runflats. I've yet to back off the sway to the lowest setting (I don't drive the car much as I take the El pretty much every day) - anyone have experience with this?

I've never had winter tires before - I've also noticed the braking distance/stability is reduced quite a bit as well.

 

Winter tires suck on dry pavement compaired to summer tires. About the swaybar settings, if you like oversteer as I do, leave the bar on stiff. I have the 22mm Alta bar. Contersteering in winter is one of the great driving pleasures, just be sure your skill can control it. If you have doubts, just set the bar to soft and go with some caution, you can always use the handbrake to start oversteer regardless of swaybar settings.