Nice, modern apartment, comfortable bed and an excellent host is maybe the best summary of Karsten's place. We didn't see Karsten too much, but when we did it we always had a nice talk.
The location is good, though walking to the centre would be a bit far. There are several good public transport options though. Countless restaurants are near.
Dinner: We recommend Blackbeards for burgers (reserve a table!) and Trattoria Terra Sarda for Italian.
For breakfast/lunch: Bekarei and Beakers, the latter is also a fine place to go for a drink.
The neighbours can be a little noisy, but usually it's not until late nor is it very long. And there's little Karsten can do about it probably. ;-)
Bottom line: we had a very pleasant stay and would recommend Karsten's place to anyone, especially single travellers or couples.