I think the biggest difference is that Detroit plays like a team, while Pitt plays like a squad dependent on a couple of players. Detroit also takes advantage of every break, or so it seems. I think Pitt has the players, but Detroit has the team, and teams win championships, for the most part. I certainly do not count Pitt out. The series does not start until someone looses at home, or we get to a game 7.
The main difference Ive noticed is that Detroit goes 100% all of the time. THe Pens will have lapses where they keep skating backwards, or stand around instead of being aggressive and poke checking / sweeping the puck off of a Detroit players stick & many times in this series their mental lapse/ brief spurt of laziness has led to a Wings goal.