I think the most widely accepted style of driving during break-in is to not maintain steady speeds for prolonged periods and keep the "hard braking" to a minimum.
I've owned and broken in several Ford SVT products including two 2nd generation Lightnings and two Cobras. I drove them all hard straight from the dealer, however I always varied my cruising speed for the first few hundred miles and never accelerated hard unless I had plenty of room to slow down without riding the brakes.
Also keep in mind our motor is running a total synthetic oil for lubrication. In most applications where synthetics are involved, the break-in period is not as critical.