I stayed at Nikolai’s flat for 10 nights, and it was a great experience. It is a compact, quiet space. Perfect for a single traveller, or a couple. Kitchen was nice. Roof top views are stellar, and location is very convenient for buses/trams. The one in front of the building takes you directly Brighton Beach. Along with short walking distance to trams that would take you to St. kilda, and down to the CBD.
I have not met Niko in person, but he is very considerate, and thoughtful to check in once in a while to ensure your comfort, and to answer any questions. I mostly had direct contact with his father Vladimir. Who is equally thoughtful, and considerate. We met briefly when I was checking out for nice, friendly chat.
My only criticism is that the toilet is an old fashioned syphon/pull system which is a bit tricky to handle.
Otherwise my experience had been wonderful, and would definitely recommend to other travellers