The stay at Sonja and Alp’s place was fantastic! The location is super central, just a few minutes from all kinds of public transport. The Saturday flea market that’s basically next door was also a lot of fun.
Apart from all that, If you enjoy a tidy, lovely apartment equipped with everything you need just like I do, Sonja is a great host whenever you're in Berlin. I stayed for one night only, but would have loved to stay longer!