We got an Explorer ST for my wife, its extremely fun to drive, VERY fast and corners like its on rails. It is a much harsher ride, however kind of expected with the 21' wheels and the sport tuned suspension. IIRC it has the street pack and the track pack, man can it hold a corner and stop on a dime.
I don't think ST Line SUV's are meant for a plush ride or off-road, but more so street and track performance. Haven't had the opportunity to drive the Edge ST, but I do drive the Edge Titanium's as rentals all the time, they are great cars, super comfortable and one of the best wide windshield views I've experienced.
Definitely pulls away from the Raptor on the freeway from a roll. At least when my wife's driving it does. LOL