Tuning cars should always be about more than just a tune, whether via a flash, or a piggyback ECU. It seems to me, having come from the VAG world, that the BMW community is rather conservative. Of course a tune increases stress and heat; that's a given. But, done properly, you can accommodate these within reason, with cooling improvements, as well as adding big brakes, suspension, etc. That's what keen car fans do...isn't it?
In addition, car manufacturers are conservative. They have to be. As owners, we can choose to be less conservative, although everyone's appetite for risk varies. For example, my preference with a car like M135i is for a very mild, hopefully flash-enabled tune, which merely gives me back the manufacturer's very conservative margin, and which provides a tune that takes advantage of available fuels. I'll not rush into this; I want to see these products become available, and to get a sense of their effect and suitability. I doffs me hat to those who are on the bleedin' edge
