Nicolas' apartment is beautiful. We arrived late at night from our flight which caused no problem at all and were welcomed by an extremely tidy and clean apartment. The bed is very large and comfy and during the day the living room and kitchen were very bright meaning they were lovely to relax in, especially with the windows open given the lovely weather we had! Having the flat on the 5th floor with no lift was no trouble for us at all, until I ran the marathon! But I won't be doing that the next time we visit and hopefully get to use the flat again.
Nicolas was a lovely host and stayed in touch with us throughout the duration of our stay. We highly recommend staying here, it's beautiful, well located (right next to the Gare du Nord and very close to Montemartre) and very spacious for one or two people.