We stayed here for 6 nights in early August. The apartment was very nice - clean, tidy and lots of space. We loved the kitchen also. (Just a note, there is no microwave or oven!)
The neighbourhood is super cool, very young and and artsy with lots of graffiti around. The street is also filled with many restaurants and cafes - we loved Sadhu (delicious Indian/Pakistani food) and Aldemir Eis (ice cream in waffle baskets!). The apartment is also close to the train station and the famous East Side Gallery is just across the river.
However, there were a few negatives. On our last three days, construction works started on the building, right outside the room, and in the early hours of the morning. They were extremely noisy. It would have been helpful to have known beforehand. The wifi was also very slow (as mentioned in a previous review) and at the time, Berlin was going through a heat wave and there is no air conditioning at the apartment, and no fan of any kind, which would have been nice.
Apart from these few drawbacks, it was an enjoyable stay.