I come here every year for a conference in town (two or three nights) - this is a hotel which just works when it comes to (a) location, (b) service and (c) room product. I have to admit that I am not the biggest fan of Accor but this brand has a good feel of quality about it. I know I don't have to worry about anything - and that's what I want when I travel for business. I also like the look and feel of the hotel and love the views over the Zoologische Gaerten (north-west facing, don't take the rooms going to the other side). The F&B area is however not my favourite and I think the bathrooms would benefit from a light touch-up.
Service-wise you cannot complain about anything. It just works and is hassle-free!