Marieluise’s apartment is in an excellent location, it’s literally 15 minutes away from the historic centre if you take the subway. It has four separate beds (actual beds, not sofa beds). She left clear and precise instructions for checking in and out (she couldn’t be there personally for check-in, but she left the keys with neighbours). Marieluise seems to be a very kind and hospitable lady, all in all.
On the negative side, the wifi is so slow, it’s practically unusable, so expect to use your phone data while there. The apartment also seems to be underused to the point of being neglected. The place was dusty in spots and it felt like spiders had nested in the place, webs and spiders crawling out of every corner and crack. While the host provides towels, I would recommend bringing your own, too.