Staying with Christian was an absolute pleasure. He was very easy-going and friendly. He offered excellent advice and last minute dinner recommendations when my dinner reservation fell through. I arrived at the apartment in the evening and he was there to welcome me and offered tea and coffee and directions to where I was meeting a friend.
The apartment is very secure and beautiful. It is exactly what you need if you are planning to be out most of the day and evening and want somewhere clean and comfortable to sleep at the end of the day. There's also good access to wifi.
The fact that the location is not central is hardly an issue because there is a metro stop literally outside the door and the metro system will easily get you anywhere you need to go. There is also a night bus and city bikes as another option.
I would highly recommend staying at Christians if you need a nice and affordable place to sleep in Paris!