There is not much difference between the teams that are in the Bundesliga and the teams that are placed as favourites. There is no way to say that Bayern Munich's performance is much better than any other team because I still see some obvious weaknesses in Bayern Munich's defense and finishing positions.
Bayern Munich is not the best if we should generalize it to other leagues because there clubs that has more better quality and performance more than them but however if what you meant is within Bundesliga I think Bayern Munich is the best on this league because they have already shown all the quality, though I'm not saying that there are no more other good clubs on this league but the fact is that they are the best for now even if there seems to be some serious lapses on there defense and there pattern of finishing but is normal because is difficult to expect 100 percent good on a club.
However if it was last season I would have say that they are not the best but this season I see no club good enough to be there rival because Bayern Leverkusen that was supposed to be very competitive has gone poor on this early time leaving Borussia Dortmund to occupy the position they were supposed to, so apart from these two teams which other club do you have in mind?.