Firstly Frank was very friendly and spoke English, we had a brief interaction but he was lovely.
The apartment itself is a fantastic place, very nicely decorated with everything we needed and more. The bed was incredibly comfortable which was fantastic after a day of sightseeing! The shower is brilliant too... a large space with a standard head as well as a sunflower head.
The location is great and it is very easy to access the centre and the airport alike. The street itself is beautiful too! There is a supermarket just around the corner, a huge park opposite, some restaurants and a great burger place. The train station is 5 minutes or less from the front door too!
This is a fantastic spot for anyone visiting Berlin. We found everything to be just right for us! Strongly recommend and will do to anyone that asks!