Amelie's apartment is very nice, big, and beautifully decorated!
It's definitely the perfect romantic location for a stay in Berlin. It is very central, the subway is a few minutes away, the area is very fun, full of young people, bars, clubs and good restaurants! I was able to walk to Alexander Platz in maybe half an hour (in case you like some exercise).
The staircase to the apartment is not the best, since it's very old and a bit dark, but it's not a problem, you forget all about it when you walk into the apartment.
It was a very lovely stay, I'd definitely recommend to book with Amelie!