i think Real are playing to their max potential..
i know that they have all those stars u mentioned, but They dont have a great defense. Thats 1/3 of the team, so i think the results they are getting are as best as they can do.
If u talk about potential: AC MILAN....They have great everything...Defense, keeper (abiati, dida!!), Mid, and Attack......
Arsenal, Munich, and Barca also have great potential.