Christian's Apartment is just awesome. The location is just right in the middle of the latin quarter - it's very easy to get good food, supermarché, hang out place etc. Regardless it's in the middle of the action, the apartment is very quiet - once you get in, the noise from outside is subdued.
The check in process was very easy - christian himself helped us to settle in and explain everything. The place itself is very lovely - all the comfort and amneties you need for your stay in Paris.
Would I come back again if I'm in Paris? Definitely :-)