All in All, for the worth of the price per day, it is the most economic option we could get in the centre Berlin with the sacrifice of comfort. For the same price, you could only get a bunker bed in 8 ppl shared room in hostel or most of hotels.
However, cleanness is a problem. bed sheet and duvet is not really clean, and it has sign of somebody has been used before we checked in. This is actually somebody's flat room, with trash bin remain full in the room as well.
Check in is also a problem. As you already notice while browsing through the public reviews. the host is often not onsite to do the check in. His flatmate did the job for him. My personal experience this time is the host text me 30 mins before the regular check in time which is already late at 1pm that his flatmate could not do the check in and need another 1 hour to come back to the flat. So we have to wait for another 1 hour for nothing which is really annoying.