Love it all the way across the board. Not having a 400hp V8 under the hood would hardly be enough to deter me from buying the car (were I in a financial position to do so). Besides, 400-500hp is nothing more than a factory installed, fully warranted FRPP Supercharger away.
And in the end, I'd rather have a blown small displacement engine that maintains all of the fuel efficient characteristics from the factory under normal cruise, with stump pulling torque and horsepower at the flick of the foot, than a large displacement engine that still won't match the horsepower and torque characteristics of a PD blown 4.6L 3V and takes a hit in fuel economy anyway?
The reason the Mustang is still cheaper than its competitors (Camaro & Challenger) are because its still got the same “tried and true” 4.6L 3V under the hood. Don’t some of you be fooled into thinking that with a new 400hp engine, the price would remain the same. You're just gonna pay more for it in the sticker.