I've stayed there twice and both times have been underwhelmed by the room decor, which is quite 'heavy' in a classical style. Never had a club room, though. Location is good for tourist stuff (walkable in up to 30 mins to Checkpoint Charlie, Brandenburg Gate, the Jewish Museum, Museum Island etc) although you'll need to take a cab or metro to KaDeWe etc, and there are plenty of shops, coffee places etc in Potsdamer Platz, if you count having a Starbucks near your hotel as a plus point. The restaurant is slightly odd, being based around an old cafe which was taken apart and then literally reassembled inside the fabric of the new hotel. Good boutique selling R-C and other goodies!

I'd be tempted to try the Rocco Forte property next time, purely for a change, but the R-C is a solid choice.