The 135I auto is faster because it stays in boost. Since I don't power shift it has to spool up between shifts. The car was a lease and I couldn't justify buying it with the high residual value. I also had chronic fuel pump failures. I'm on the third pump in 18k miles. The last one just quit getting on the freeway. BMW apparently has given up trying to fix these high pressure pumps. The new motor will be a single turbo without the high pressure pump.I'm hoping to have good luck with the SRT6. Certainly the price was right.