Lovely hotel in a great location, easy to walk to Potsdamer Platz and into the Tiergarten; also several U-bahn stations near by.
Interior of the hotel was really nice, well furnished. Staff, in the main, were friendly and helpful
Couple of things to be aware of - they don't provide tea/coffee making facilities in the room (I think to reduce waste); you can go to the bar to get them but it's a bit of a pain.
Breakfast got very crowded when we were there at 9am (peak time i guess)...they don't have quite enough space and the buffet area is quite small (they also only seem to have a policy of restocking things on request).
Finally, there is no AC in the rooms so they do get warm - we were there in a warm September and would guess it's a little uncomfortable in the summer (there are ceiling fans)
But we'd still recommend if none of the above would be a problem for you.