I booked this apartment for my mom and aunt when they visited us in Berlin. They were very happy with their stay. The place was clean and had everything they needed for a comfortable time. The kitchen is well stocked, clean and has a dishwasher and washing machine. My mother said the bed was very comfortable and my Aunt slept on the large couch, which she said was also nice.
Some Airbnb places I have been in are like hotel rooms, but this was very much a lived-in apartment. We found some toys which the visiting toddler could play with. Overall it was cozy and pleasurable.
The only thing I would note is that the elevator does not come to the exact floor, but it has about 6 steps to walk up. Just something to watch out for if you can't do any steps.
And finally, Biggi was very easy to communicate with, very flexible and very kind. Thank you!