As a Berliner, I can't quite comment about the hotel quality, but about the location: I wouldn't go with the Intercontinental because it's well outside the historic center and also a relatively long walk to public transport (Zoo or Wittenbergplatz). I would only consider it if your primary interest is highend shopping on Kudamm (but then the W-A is better) or if you are a state guest (it's the Berlin high-end security hotel).
If you are interested in the historic Berlin, go with something near Gendarmenmarkt (Hilton, de Rome). Some Hilton rooms have a beautiful view to Gendarmenmarkt, but make sure you get this view when booking. Or go with Adlon on Brandenburger Tor. Public transport is nearby in any case.
If you are more interested in the modern (somewhat artificial) Berlin go with something on Potsdamer Platz, like Ritz-Carlton, Marriott (beware of loud street) or Hyatt.
Oh btw, if you're about high-end dining, Berlin has 12 restaurants with Michelin stars. If you are at Gendarmenmarkt I can recommend Vau (http://www.vau-berlin.de/en/), especially the six-course dinner menu. The reinstoff (http://www.reinstoff.eu/english) is also excellent, but significantly more expensive because it's 2 Michelin stars

Regards,
Steffen