I stayed in the appt (nr 3) for 2 nights to visit my daughter in Neukölln. The appartment is quite spacious, well enough equipped and very clean. Very good shower!
Location is super: 5 min walking to Station Neukölln and 3 min walking to Biomarkt und Aldi.
It's just the short stretch from Karl-Marx-Strasse to Walterstrasse (Ringbahnstrasse) that is filthy with a lot of rubbish on the pavement and an unpleasant atmosphere. But as said it is only a short stretch.
I would really recommand the appartment.