Very easy check-in and check-out; Pierre was very kind to allow us to leave our baggages in the apartment after check-out time the day we left, and managed to provide us double keys, more towels (only one each was originally provided) - and a bottle of wine as well.
We didn't use them, but the apartment is fully equipped with home devices, such dishwasher and laundry machine; there is free wi-fi, and no TV (that we didn't miss).
There is not central heating, but a hot-cold air conditioning system in the living room (meaning, not in the bathroom and bedrooms); we didn't switch it on because weather was fine and the temperature was ok.
Essential toilet facilities as soap and sanitary paper are provided, but not shampooing, shower gel and so on.
The place has an it's own personality, because the host lives there when it is not rented. That means that you'll find personal belongings - and also food - inside.
Rue Biot is very lively and safe, with a lot of nice cafes and bistrots; we have a very plesant experience at Strobi, a french cuisine restaurant along the street.
You will be within walking distance (15 minutes approx.) from Montmartre, and from rue des Martyrs as well.