The apartment exceeded all expectations. HP was there to kindly greet us and allowed us to drop off the luggage early. He also made a couple of recommendations about local shops that was very helpful.
Location was great - restaurants, cafes, quirky shops (stationery/gift shops) right on the door step; easy to get to from Berlin Schonefeld Airport (S9 direct to Warschauer Strasse and then a couple of stops on M13). You are definitely not far from a bus/tram stop.
For eating places, I would definitely recommend New Day Vietnamese Heritage Food restaurant on Niederbarnimstrasse (towards Frankfurter Allee); Kaffeehaus Kuchenrausch for breakfast/brunch (the eggs benedict is delicious); Delabuu for ice cream rolls; Strychnin store on Kopernikusstrasse does 1950's retro vintage fashion, really beautiful, quality clothing; and they're all within walking distance.
The flat itself is on the second floor (no lift) and very quiet (even when you leave windows open while you're sleeping). It was clean, quirky, and well equipped for all your needs. The big room was very comfortable and roomy; the king size bed was very comfortable too. The smaller room is a bit stuffy when the weather is hot (30 degrees C for example) but then so was the big room so a fan is definitely needed for the small room. But I'd say it would be very cosy in cooler temperatures. We met Gosha who checked us out and she was very nice & friendly.
All in all, 10 out of 10 for the Artist's Apartment and I would definitely come back and stay.