The good: The location of Robin's place is absolutely perfect. We loved the neighbourhood, and the view over the church from the roof terrace is gorgeous. There are so many amazing bars and restaurants nearby, and it really feels like you're living in Berlin as a local, not just a tourist. Robin has great recommendations for things to see nearby. It was very quiet and the check in process was super easy. It was great to have a washing machine and an elevator as well! The place is well-laid out and a good size for a couple.
The less-good: Unfortunately, there were a few things that made this stay difficult for us. One was that the fridge wasn't working, meaning all the food we bought spoiled and we weren't able to keep anything cold. Robin was away and not quickly responsive to this. Apparently they had been having issues with it but we weren't informed of such. It was also extremely hot in the apartment, and there is no fan or AC (which is common throughout Germany, so we weren't surprised, but it would be nice to have a fan). There were major storms while we were there which meant we couldn't leave the windows open, so it was very difficult to sleep. Additionally, the blinds to the roof terrace (which is lovely) broke while we were there, so we couldn't access the terrace for two days. There was a lot of personal stuff around - clothing, stuffed animals, books, etc, with no place to store or hang clothes or put suitcases, so I wouldn't recommend it for a longer stay.
Overall, we loved the neighbourhood and the roof terrace (when we could access it), but the apartment could do with a bit of upkeep. Hopefully those issues will be fixed soon!