The location of Katarina's place was perfect for our trip as it was very close to Tiergarten and most places we wanted to visit. The neighbourhood is full of cafes, restaurants, bakeries, supermarkets and there are plenty of electric scooters and bikes on the street or only a few steps or minutes away, which worked great for our family.
The main drawback is the ongoing construction next door, which was made worse by the hot weather as we had to keep the windows open to get fresh air to keep the temperature down while sleeping and the construction started early each morning making it hard to sleep once the noise would start. Having said that, observing the work from the conservatory while having breakfast and coffee was an added bonus experience we enjoyed! ;-)
The apartment had relatively basic and lower cost furniture and appliances but that was sufficient for our family as we mostly looked for a functional place and the place was pretty spacious and offered plenty of room for our family to rest and relax after the busy days visiting different sites in Berlin.
I would like to emphasize that the check-in / check-out process was very seamless and worked very well for us even though we arrived past the working hours of the office managing the place and left early in the morning to catch a train before the office was open on the last day. The communication with Katarina and the office made the whole process easy.