Engine break in still recommended?

When I bought an ML430 2 years ago, the salesman said it's no longer necessary to break in a new motor. I didn't listen and did a "whip" method for 500 miles. 36K miles later, I don't need to add oil between service visits (10K mi.), engine is running strong, no spots in my garage floor; never had any engine-related problem at all.
I just picked up my new toy, a CLK55 AMG cab, and I heard the same thing. Now, I'm dying to let this baby rip and really having a hard time holding back! I have just under 200 miles and it still feels tight.
So what's the verdict on this???