The Stoptech rotors will last longer from my experience on my 330. I had a BBK which used the OEM euro E46 M3 rotor which is a similar design to the E90. With that said, you can't be lazy and not switch pads from street to track. If you use track pads on the street, they'll chew up your rotors. The benefit of having the ST BBK is that its x100 easier to swap pads so no excuse.
I wanna say the ST60 kit fits under the rear OEM 18s. In fact I will try and remember to do a test fit on 5/5. I wanna say the front OEM 18s may fit with a spacer from the pics I've seen of the rear OEM 18s over the ST60s.
I do agree that the OEM brakes leave something to be desired...I'm going through my front PF01s pretty quickly. About half done with 3 days of use.
2015 F34 328iX GT Glacier Silver
2011 E90 M3 Monte Carlo Blue
2004 E46 M3 Imola Red
Last edited by bigjae1976; 04-26-2012 at 08:19 PM.