Mark was super nice and welcoming. The apartment had a nice, sharing-friendly layout as the guest-room was located in the opposite side of the flat as to where Mark lived. We had our own, private bathroom with satisfactory facilities. Mark was quick to respond regarding check-in and check-out and very helpful in general. We initially hoped for a place to stay at night and travel to the most central part of Berlin to spend the daytime there, but we found the area at Mitte nice, cozy and authentic. Would recommend.