This apartment is a good choice for spending a few days in Berlin. All services are available very closed. The transport is located one minute, so it is very easy to take the metro or urban trains to get downtown or to move to any other area of ​​the city with the "ring" train.
The apartment is comfortable and soundproof, it is not noisy instead of being located in a very busy street.
Daniel is always available and ready to help for any information. It make you feel confortable. The bathroom is shared with another room, but I did not meet anyone during my stay. Everything is modern and comfortable. The general perception is good.
There is no microwave, I think it would be more comfortable mainly for breakfast or to prepare a quick snack. In addition, the bed is small and not comfortable enough, but it is a subjective perception. I am used to a firmer bed. However, there is a comfortable sofa bed in the room. Finally, there are no window blinds but it is quite common in all the northern countries that I visited. I think there is a cultural issue. In Latin countries, we are more used to privacy and the darkness to sleep (fortunately I had my travel kit to mask my eyes!) So if you are used to sleeping in the dark, there are no problems, but it is good to take your mask.
That said, Daniel's apartment is a very good option that I highly recommend!