Nope, heard of many, but from what I gather most stating such haven't even driven the Ecoboost, the 3.5L one anyway, then with it tuned, it's really fast!
The low end torque of the turbo's is really nice, but the downfall is it makes it too easy to spin* the tires, especially in off road situations where you don't want to spin the tires....
Yet to tune my 6.2, but I also own a 3.5L Eco, both are basically stock engine wise, only the 3.5L I bought a tuner. Personally, short of having more off road time in my 3.5L and really getting a better feel for the how that low end torque will respond in certain climbs, I would rather have the 3.5L in my Raptor.