We haven't met Amad in person, only his niece but he made sure to call us if everything is okay.
The apartment is at the fourth floor (and the elevator requires a special key so we couldn't use it). It is really big so our bathroom was quite far. The cloudy weather made the whole place seemed to be very scary (especially at night). Another problem were sheets. We had only one thick sheet and one thin sheet so my friend who was having the thin one was freezing at night.
The apartment's location is great though, just two tram stops from Alexanderplatz. Also I love their cat, it's super nice.
All in all, it was doable but I would expect more for such price.