I stay in the Westin Grand probably 4-8 times a year. I do a fair bit of business in the area and so as a business hotel I would say it is clean and relatively standard. its not the best business hotel I've stayed in. The Gym is small and not complete, but fine if you want to run a little and lift very basic weights. The last time I stayed there they moved me from my reserved queen bed to two doubles pushed together which basically means you are sleeping on one side in a double. The location is great, its very central and ideal for seeing the main sights and being able to go on a run in the park. All that said, I put my last trip at a 3/5 because they changed my room on me.
The best hotel to stay at in the area is the Soho house followed by the Ritz Carlton, sometimes you can get lucky and they are the same rate as the Westin Grand. I would also say this hotel is not close to all the happening spots in Berlin. Soho house is better situated for nightlife.More