When you guys say throttle lag, what exactly are you referring to? On my 528 he max torque clearly kicks in at 1500+ rpm. My biggest complain is the 1-2 second lag that occurs when I put the pedal to the floor from ~20mph.
If I'm in traffic going, say 20 mph, and I want to go around someone to get through a yellow (Exact scenario yesterday) I pulled my car in to the other lane at about 15 mph, put the pedal to the floor, and waited.... 1-2 seconds later, i shot to 40 mph in no time.
Is this experience similar to what you guys are having? I bought my car 3 weeks ago, the manufacture date was June of 2012.