This is a lovely studio apartment for a short stay for a couple, or a longer stay on your own. It can actually sleep more than a couple, as it has a sofa bed, but there are no curtains or blinds in that room, and with two large (beautiful) windows, it is very light, so unless you wear an eye mask, it would be difficult to sleep beyond dawn.
The apartment is spacious and very tastefully decorated and furnished. The bedding is feather-filled. The bathroom is lovely and new, and the kitchen provisions are enough for minimal cooking and food preparation (although a microwave would be welcome).
The apartment is located in a great spot. There are lots of cafês, bars, and restaurants very near by, but the flat itself is very quiet. There is also a great street market pretty much just around the corner, along the canal. Really good food there, with plenty of vegan and veggy options. You can also walk to the central area (e.g. the Mitte) if the weather is nice and you feel like a more extended stroll (30-ish mins), otherwise you can just get onto the underground and you'll be in Alexanderplatz in just a few stops.
If you want to explore Berlin, but keep your base off the bitten track, this is a wonderful place.
The host, Philipp, is great. He is helpful and attentive, and responds quickly to messages.
All in all, this is definitely a top find.