Cubs Unbeatable?

Are the Cubs the team to beat or are they just going to choke in the playoffs like they always do? With the Cubs 4 1/2 games up, and the best record in baseball , it's like when Arimas Ramirez hit's 2 HRs and Ryan Demster pitchs a complete game you expect Alfonso Soriano to hit 2 HRs of his own. But with Prince Fielder and C.C. Sabathia getting the job done the Brew Crew could be on the Cubbies heels in late september.