Vincent's flat is very charming, in a quiet street in the 20ème of Paris. You should be good on foot, because there's many stairs to go all the way up to the sixth floor, but you will be rewarded with a warm and welcoming little hideout that offers all you can ask for.
We were three people, two of us were sleeping in the living room, the third person was sleeping in the child's room. We slept pretty good because of the silence outside and the comfortable mattresses - the child's bed was a little wobbly though.
A big plus in the cold wintertime where the radiators in the flat that got the space warm in an instant! So we could enjoy watching the snow on the small balcony even more.
Metro connection was good as well, there's a metro station close by.
I recommend Vincent's flat to everyone who wants to visit Paris and likes to stay somewhere close to Père Lachaise!