Pros:
-Great location
-Good communication with hosts
-Big, bright room, looks exactly like the pictures shown
-Very clean
-VERY comfortable bed/pillows!
-Helpful guidebooks and nice big map in the kitchen indicating the hosts' 'best of' in Berlin.

Cons:
-There's only one shower and toilet shared among 4 rooms. If each room is occupied with a couple then 8 people sharing the facilities isn't very convenient. It was clear on the listing that the washroom was shared but it should list between how many rooms. There were queues in the morning and being in the Maritime room made checking to see if the washrooms were available more difficult, as you'd have to constantly check back and forth since it's the room furthest away from the facilities. Maybe a sign-up sheet for morning use would be helpful.
-The room itself was nice, but I'd choose a different room to stay in if I came back again because its location in the flat isn't the greatest. You have to walk through the kitchen (the only common room in the flat) to get to the washroom and in the mornings walking through the kitchen in PJs while other guests were having breakfast was a little awkward.

Overall, very nice stay!