We stayed at Gregory's place last week. We experienced a few issues,like the place did'nt have enough ventilation(only a very small window). As we stayed in summer,it was very hard to sleep at night as there was no fan or aircondition. The room gets really hot in summer night.
The place had a funny smell in it probably because of lack of ventilation.
The bed sheet + towels felt damp due to humidity and lack of ventilation i think.
However there were quite a few positive things I must note. The place is in a very convenient location near a metro station so that makes it very easy to get around paris. Its also close to plenty of cafe,restaurant, bar etc.
We found the host Gregory very responsive to our communication and helpful. We met his friend Armand who was also very helpful and nice.