Follow BMW's recommended break-in unless you want to risk losing your warranty. It's a new engine guys, and you really don't want the finger pointed at YOU if BMW's little V8 gem has teething problems.
You guys would be amazed at what the ECU can track.
My buddy with a new Exige S followed break-in dutifully, then went to the dealer for his post-break-in service. Keep in mind this is a crude British-Toyota product with very few electronic systems. HOWEVER... the service department gave him a big long printout of everything the engine had experienced over the first 1000 miles.
It showed what percentage of time the engine was at full throttle, 20% throttle, 2% throttle, every amount of throttle - you get the idea. But wait, there's more -- it also recorded the same for engine rpm's and percentage of time spent at different rpms... but there's even MORE! It also recorded at what temperature both the oil AND the coolant were, while the engine was operating at those various rpm's and throttle position (IOW, they don't want you driving hard on a cold engine either -- common sense, right??) It also recorded how many clutch dumps had occured (high rpm, sudden accelleration in low gear)
It was really astounding. Lotus is watching. Warrantys could be pulled. I wouldn't doubt if BMW or any other manufacturer does the same thing. These engines aren't cheap. The break-in on our 997 GT3 was a painful 2000 miles, but we followed it religiously since that engine is about $30K to replace.
Following break-in puts the liability for future problems on the manufacturer, not on you. Just do it.
I also recommend as above... after the first 300-500 or so very gentle miles, you want to run the engine up to its max recommended rpm, then lift off and let it engine-brake down... in every gear, without going WOT, just short of it. Let the engine and trans experience a variety of conditions. And of course, always warm it up before driving hard. Oil temps at minimum of 165-170 IMO.
I would never take my car for service until after the break-in is finished. You don't know what the lot monkeys are going to do.