We (a couple) satyed 4 nights at Marie's apartment. The address was easy to find and on arrival we found everything neat and clean.
We didn't get an opportunity to meet Marie in person, but found her helpful and the key arrangement was also convenient.

The positives and negatives from our experience are,
+ves:
Metro and bus stations are right next to the apartment building. There are many food and fruit shops in front of the building including a super market. Kitchen is well equiped with all the cooking utensils, refrigerator, baking oven etc. Bathroom is clean with a nice shower and a washing machine. Apart from the bedroom the house has a living room and a small balcony. Wifi signals throughout the apartment.

-ves:
Apartment is on the fifth floor without any elevator, which is not very pleasant especially after a long day of exploring. The neighbourhood is busy and loud and also slightly far away from the city center. You need to change two Metro lines to get to the main tourist attractions (roughly 30 minutes). The apartment in itself is quite old and lacks fresh air and opening the windows could be noisy.

If you don't mind staying in a not-very-central and busy neighbourhood then we definetly recommend Marie's apartment.