I've had mine for two years now and I love them on my 128i. Smooth, quiet, confident in rain and still has sharp handling. They replaced the OEM craptastic Goodyear Eagle runflats, which were loud, hard as diamonds and super expensive ($425 EACH!). I got the set of AS3's for ~$800 installed.
Couldn't tell you the exact wear though, but definitely two more seasons for sure.