Yes - we're back. FWIW - I agree with you about the area around the Europa center. But I disagree about Potsdamer Platz - at least the Sony Center. We went there a couple of evenings to have a drink - eat - walk - etc. - and there weren't many tourists in sight. Mostly younger Germans who were there to catch dinner and a movie. Some people might not consider it the most scenic place in Berlin (although I really liked the architecture) - but it is more like a movie/food mall for locals than a tourist trap.
Note that for anyone in this area (Potsdamer Platz) - there is an excellent collection of large scale outdoor sculpture scattered around the area (works by Jeff Koons - Richard Serra - etc.). It's part of the Daimler collection - which also has a small free open-to-the-public museum in the area (it's kind of hard to find - but you can find instructions on the web site - as well as a map of where the sculptures are located). The Daimler building itself is an extremely interesting piece of architecture. Robyn