Agnes and her husband were both very welcoming and kind during my short stay in Berlin. The photos were accurate and the room was perfect for a quick trip. I don't know if it was all the walking I did, but I swear I never fell asleep faster. The apartment is in between the Moritzplatz and Checkpoint Charlie U-Bahn stops, but there are buses in between, so it's a very convenient location. You're right on the edge of Mitte, the historic part of the city, so it's a great jumping off point. I'd definitely recommend Agnes' place if you're looking for a convenient, easy place to lay your head.