We booked Michaels apartment because we were in town for a wedding and traveling with a little kid and a caretaker. Communication before the trip was nice and swift.
The check-in was very easy (key-box right at the door) and we still met the person that was cleaning the apartment (which was fine, we arrived some minutes early).
We however noticed that the bed sheets where far from fresh. I checked with the cleaning person that assured me that they just put them up. This was not the case as the bed sheets on the bed had make-up stains, (minor) blood stains as well as hair on them. In addition to that the apartment was not cleaned well - there where empty bottles left in the kitchen and dust bunnies everywhere; a highlight was a train pass under one bed from February 2020 (!). There was a laundry bag in one bathroom that was full of empty laundry. This meant we spent roughly an hour to make the place habitable for a small kid and us. In addition, the "fully equipped kitchen" featured exactly one coffee cup.
Upon reaching out to Michael, he managed to sent someone to the apartment that dropped off (they did not make the beds but really just dropped of new sheets while leaving all the dirty stuff there) fresh sheets and coffee cups. Michael apologized and we agreed on a discount for the circumstances we found the apartment in.
In sum, the apartment would have been a decent experience would it have been cleaner. It has seen a fair share of guests come and go but is generally well done. It is splendidly located if you want to experience the city and close to public transportation as well as a large amount of shops. Also, one of Berlin's best "Currywurst" (at Bratpfanne) is within walking distance.