First track day was at 1526 km for me changed my oil at 6000 km car is currently at 8000 km no issues with it besides the fact that is smoking fastSo once past 1500km, you're not breaking it in anymore - go nuts!
Stop light to stop light made a A8 4.2TDI look like a Golf 
Day 7 of ownership took it autocrossing (just swapped wheels) - during which it had multiple trips to redline. It was still on temp tags. Friend recently brought one with dealer plates still on it (green PP2). Car works fine, no ticking or other BS.
How many Cobra Jets will ever see 100,000 miles even if you ignore engine refreshes/rebuilds as essentially being new engines with their own break-in sequences?
Varying the speed is still necessary - it's mostly about the effect rpms have on where the oil gets splashed against and where it doesn't. Think in terms of local hot-spotting if oil splash doesn't reach every surface at least occasionally.
Sort of how I'm seeing it as well. Of course Ford wants everyone to play it extra safe, and it's certainly not going to hurt to do so, but once you've looked at the type of torture testing the coyote has endured with the engine left functionally perfect afterwards, it's pretty unlikely in my view that running your car hard several times in the first 1,000 miles is going to have some lasting / significant impact. I'm not out pushing the car to redline every day but I've done it 5-6 times (all after the 300 mile mark) in the first 1,000 miles and I'm not going to worry about it. I've driven every other new performance car that I've owned this way (including turbos) and every car was in excellent condition by every measure when sold. If Ford really thought that hitting redline in the first 1,000 miles was likely to cause significant harm they would program-out the ability to do so, just as they have the ability to hit redline in neutral (which all agree is a horrible thing to do). Many, myself included, want to feel and show-off those 460 horses after spending that money and may not feel like waiting a month or two and that's probably exactly why there is no such limit imposed by the computer. The engine may be a bit less perfect at 100K than it would have been with a more gentle break-in admittedly, but I won't own it then, and it will have been long-since traded in on the next generation. Every month owned is going to be a blast, and I have enough warranty to cover my expected ownership, so not worried. The line about not "driving too fast" during break-in gave me a chuckle. I'm pretty sure that driving for hours at a steady 100 MPH rumbling along at 2500 RPM or whatever that works out to in tenth gear is nothing for the engine compared to high RPM romps.
Ford is right - out of the showroom vary speed, don't rev high, no hard throttle, and especially, don't ever lug the engine! On my '12 GT PP I changed oil at 500 miles, switching to full synthetic for the life of the car. Changed oil again at 1,500 miles, then next at 5,000 miles and every 5,000 miles since. Car presently has 222,000 miles, burns no oil, and on a 400 mile trip last Thursday averaged 28.9 MPG. Maybe all of this isn't necessary, but obviously none of it hurt my Mustang and the only repairs to the car have been the oil pressure sender at 216,000 miles and the clutch release bearing at 220,000 miles. Oh yes, and front wheel bearings but I blame that on the crappy roads and streets in Minnesota.
