...until you take it back to the dealership for any engine, turbo, or transmission work. The EcoBoost is a good engine, but it is known to have problems (I have had two that needed to be replaced) and both times the first thing that Ford asked was if it had a tune.
I'm not trying to make this 6000lb Expedition a race truck (that would be the dumbest thing). I just want a bit more throttle response and the $250 the PC cost me has been more than worth it. You can just unplug it at anytime and pop it in to your next Ford. It works on any F150 since 2010 (and many other Ford vehicles) without a reflash/tune. You can also change the settings on the fly if it is wet/slick outside.
Expensive for what it is? Yes. More cost effective than a tune (in my scenario)? Yes