I own Kumho Ecsta ASX's on my ti (225/50-16) and they have been great. Not sure how they will last, but I know BMW's eat tires. A friend of mine swears by the Pirelli P-zero nero m/s, but his only last 30k, too. Also, I have heard that most people who up rim sizes beyond what the mfg offered often compromise the suspension by increasing unsprung weight, or changing the offset, ect. Anyway, I think the ASX handles well in rain and so-so in snow. Check out this road test on tire rack:
http://www.tirerack.com/tires/tests/...um%3D25WR6EASX