I can't see this honeymoon with the fans lasting long as McCarthy loves power running and similar to Tomlin he is old school conservative when it comes to innovation.
Supposedly Rodgers wanted him but from I remember when he was fired in Green Bay there were clips of Rodgers and McCarthy arguing about plays after a call blew up.
Also he will be the shortest tenured coach for the Steelers since the golden era began as Noll, Cowher and Tomlin all coached the Steelers for more than a decade. For McCarthy to coach for that time length he will need to be in the Pete Carroll age range to have that length of tenure.