I like the F15 much better than the E70. The Adaptive M suspension makes the F15 feel smaller and more athletic due to the X5 being flat through the sharp turns. I've installed MPPK ( M performance power kit ) BMW only claims the MPPK adds 20 horsepower and 32 ft/lb torque, but those figures are highly conservative based on user results and dyno from Dinatronics saw 337 hp and 377 tq. I've also installed Racechip piggyback tune which further increases power My E70 had standard suspension and standard 19" wheels so the drive was uninspiring compared to my new X5