I spent last weekend at the RC and had an excellent time. We were also pending between Hotel de Rome and RC but ended up in the latter as the Virtuoso rate includes Club access (great service as always from DavidO).

I am not too fond of the RC's quite opulent interior but found the property to be very well maintained and excellent service. The lounge is nice and we had quite a few good glasses and some light food. Very convenient. We had breakfast in the brasserie as this was excellent and far more elaborate than the offerings in the lounge.

Also went over to the HDR for a drink. Nice ambience in the bar and the whole property has a classy, modern vibe - although far from spectacular IMO. I fully agree that RC's location is not Berlin's most charming - however Potzdamer P is very convenient for exploring the city.