I find the fusions power with a tune and usual mods, to be very linear and predictable both on the track and the street. Imho the perfect car for those who need the extra seats for family and younger children. Ford really did their homework correcting the simple things muffed up on the sho platform, ie drain plug on the front PTU, warning indicator on the hood if its not closed, 400lbs lighter, standard sport mode. 3.26 final drive ratio. Im very impressed with what a great job they did on a classic sleeper.
My mustang GT is akin to a caged animal whose motor wants to rip itself out of the engine bay and take off down the street, loll It takes quite a bit to figure out for launches without torching the rear tires (275/40/19s) but the coyote drivetrain is simply excellent with launch control, track apps and line lock to help the driver, internal timers ie 0-60 through 1/4 times, lateral Gs, braking 0-100, 100-0 (in Mexico). The Brembo 6piston front calipers are simply the best brakes ive ever had ( Ive owned SVO mustangs, 05 STI, 03 Cobra and SHOs). Again Ford did their homework for the muscle car affectianato on the exhaust tuning, like a baby crying the small block v8 brings a tear to your eyes.
In contrast the Mustang is a street brawler, the Fusion Sport a hitman. Both solid choices without question.