Had to replace mine early due to a nail, an since I had a track weekend coming up I couldn't safely use a patch (wanted to get PSSes anyway), but based on tread depth I probably would have reached 2/32" replacement time at around 12K on the rears and 15K on the fronts. Those were PS2s, which have a 220 treadwear rating; the PSSes have a 300 rating. My driving is roughly 50/50 city driving and harder back road + track driving, almost no freeway driving. I don't kick the back out around turns or anything like that.
I admit I was expecting a bit more life than that but it's still worth it IMHO. The tires are great, the PSSes are a lot cheaper, and you gotta pay to play I guess!
11 M3 E92 Le Mans | Black Nov w/ Alum | 6MT | Premium 2 | Convenience | 19" | EDC | Prem Audio | Moonroof | BMW Apps | Vorshlag Adjustable Camber Plates | StopTech ST-60 380mm BBK | Castrol SRF Fluid | ModMyNav.com rear camera | OEM Euro Sunglasses Holder