A little over 2,000 miles and the rears are 40-50% worn. I don't do burn outs, not drag racer (OK, one Friday night at LACR so far, but I just clean the tires a second and avoid the water box) but I play in the canyons and desert roads a lot, and love a good drift.
My office is built into my house, so I have no commute. Probably 2/3 of my miles are play miles. I'll rotate them soon. I'm thinking with some care on inflation and rotation, maybe 7-8,000 miles.
I really like these tires. They're sticky, and they communicate wonderfully. I also like the run flat advantage. I was looking at other tires, but have decided that I'll just replace with the same.
Of course, having no commute, mileage isn't important to me, even at 8K per set that's 18 months for me. If I was racking up 15K a year, two sets every six months would get old.