We loved our stay at Lucyna's! The place was impeccable, the view was incredible (even better than in the pictures) and there was everything one might need. Lucyna was quick to reply and made sure we felt at home. The stairs (sixth floor) might not be suitable for elderly people, but we didn't mind them.
Everything was clean, there were blinds so the room was nicely dark at night (and very quiet) and several mirrors (not every airbnb-place in Paris has them, I have noticed). The bed was very comfortable, there were good books on Paris provided.
What else?! SoPi-area was full of interesting little restaurants and shops, felt totally safe, Rue de Martyrs was right around the corner, two minutes to Montmartre and easy to walk anywhere, but if you prefer the metro then Pigalle is just a few blocks away.
We definitely recommend Lucyna's place!! There is no wifi, so for someone needing that for working etc it might not be the best place, but we didn't mind.
Book it, you will love it!!