I've been reading this thread and I have to say it's quite interesting. First of, most of the comments are honest comments, not too much boasting.
But for me, the real question is lap times around a track. I'm not so interested in straight-line acceleration. I maybe stating the obvious here but BMW cars are designed as a balanced car. Just look at their testing facilities...they have one at the Nurburgring.
I really want to see a 335i vs SRT8 or Mustang GT on track doing laps.
According to this video, the 335i beats, by a fraction of a second, the more powerful and more expensive S5.
http://www.carandgarage.com/watch.php?v_id=1038
Let me know what you guys think.