We’ve just got back from an excellent stay in Berlin, the 6 of us (3 couples) had a great time. Having Trudy’s apartment for a base was great, it’s stylish, in a great location close to one of the main U-Bahn lines and has everything you need. I would say if you’re afraid of a few stairs this isn’t the place for you but it wasn’t a problem for us, probably did us good after all the food we ate!