Dortmund can be unstoppable on their day but they need all their big guns firing to do it. On top of that they don't have much coming off the bench as a plan B. I also think they can be scored against and Real and Malaga nearly did it.
Bayern have several match winners starting and several more on the bench, 2 proven goal scorers, and a similar defence although I'd argue 4 of the back 5 are stronger than their opposite numbers. Most importantly Bayern need it. 2 lost recent finals one in Munich, Dortmund winning 2 Bundesligas in a row, the manager's last game, Pep coming in, already signed Gotze for next season ... all says Bayern.
I hate Germans.