A great apartment - very comfortable (excellent bed), well-equipped, quiet and in a very nice location in central Paris (20 min walk from Gare du Nord, 30 mins-ish to Montmartre & Pigalle). Canal Saint Martin is a great area itself with lots of choices of restaurants, bars and supermarkets.
We had to work from the apartment for one day and the wi-fi served us very well plus there was enough room for both of us to work and take various conference calls.
Yves was also very accommodating with the fact that our train arrived later than check-in allowed - thank you again!
As other reviews have said, the apartment is on the 3rd floor and up a steep, spiral staircase so take note re-luggage etc.
All in all a great place to stay and we have absolutely no hesitation in recommending it.