Dallas has not seen a defense anywhere close to MIA's. People keep focusing on MIA's offense, but it's MIA's defense that has won them games. Mav fan keeps knocking down what MIA has done (meaning who they faced to get to the finals), but regardless of if you think BOS/CHI is overrated, one thing about those two teams that was not overrated was their defense. They faced two of the top 4 defenses and won. Dallas had a brutal road to the finals as well, but clinging to the fact MIA had it "easier" is silly and pointless IMO.
So while MIA has not faced a team with the Mavs offense, DAL has not faced a MIA defense. The question I ask is can Dallas's style of play (great jump shooting, no penetration or slashers/finishers, lack of one-on-one creators, very good perimeter ball movement...) beat a top flight perimeter defensive team? Can Dallas also find a way to shut down Lebron/Wade and to a lesser extent Bosh? Despite the bench argument (which everyone has used in every series involving MIA), MIA keeps winning.