I replace these tires for the factory conti ssr on my 335 xdrive. The original conti is very good however these MXM4 is just better. better in almost very area including better traction, sharper cornering and softer ride and less noise. I have driven these tires in dry,wet and snow conditions. It capable of all road conditions in Chicago, even in some deep snow and ices, it feels safe.
The only draw back is seems the tire have 1 less mile per gallon in gas, it might be due to change of driving behavior, but it is really don't hurt compare to all those gains i had. Over all, it is the best run flat i have driven on.
ps.I just went to the dealer for service, they measured the tire tread depth, seems it is also consume faster than the factory conti, but it does come with deeper thread then the conti ssr, so assume they have the same life.