Mack is a short squat powerhouse. Just the opposite of McDowell. The problem with Mack is he looks better in drills than actual games. It looked kind of obvious during that offseason with the Senior Bowl practices, etc. that Mack was playing himself into a draft position that his actual ability level didn't warrant.
Nobody in Seattle had positive things to say about McDowell. I follow some of their blog sites and forums. He didn't have the necessary attitude or practice habits even before the ATV accident. There was also discussion that his personality and cognitive ability seemed to change after the accident. Then all the off field stuff. Keep in mind all of this was an extension of his final season at Michigan State, where his play was so lazy and disinterested he fell out of the first round.
I don't like drafting jerks or signing jerks. That is an extension of the early years of the franchise, when the Dolphins did great as long as they stuck to high character guys. Bobby Beathard veered away from that by taking chances on troubled guys like Don Reese and Daryl Carlton and Randy Crowder. The Dolphins got burned. Beathard conceded he made a mistake. He said it helped him later at Washington. The character theme was so pronounced for the Dolphins following the disastrous 1976 season that the top two picks A.J. Duhe and Bob Baumhower were selected with that in mind. Every post draft article spotlighted the character aspect and how the 1977 draft was designed to righten the ship in that regard.