Martina's apartment was fantastic. It is in a great location, really easy to get to from the airport and centrally located to access all tourist attractions in and around the city. It's also in a really good spot for restaurants and grocery shops!!
The apartment is really spacious, central but in a quiet location. Although it says 3 rooms it's actually just 2 and a sofa bed in the lounge, but 6 adults shared the apartment and we found it to be perfect! The kitchen is basic but perfect for what we needed, a coffee machine was a great bonus!!
Martina was great at communicating and offering advice on how to get to her apartment from the airport, she met us on time to hand over the keys and was very pleasant.
I would say that the shower maybe needs some sort of way of attaching it to the wall so you don't have to hold it up whilst having a shower. It was manageable but a little frustrating.
I will definitely recommend this apartment to anyone who wants to stay in Berlin - it is perfect!