We stayed for a week to see Berlin. The apartment is in a semi-quiet neighborhood and is also in the backside/courtyard of the building, so no street noise. Great for sleeping after a long flight! The apt was also really cozy, just the two rooms but feels spacious and there is definitely room for everything/places to unpack.
Close to the train but also not too far to walk to central Berlin (maybe 30 minutes or so). Lots of restaurants and bars nearby within a few blocks. There is also a very inexpensive bike rental one block away.