The apartment was great, couldn't have been happier. The neighbourhood has lots of character/lots going on but is still peaceful to go to sleep at night. 10-15 minute walks to be in the heart of the action and really close to the train and tram systems. The apartment has great space (could easily hold a small family or 4 people if using the day bed) and has lovely natural light all throughout.
Communication with Maarten was incredible, he always got back to us really quickly and kindly arranged a last minute booking late at night.
If I go back to Berlin I'd definitely try and get this place again.
Thanks Maarten (and Britta and Marcus.)