We enjoyed our stay in Vladimir's studio very much. The apartment is small, with very basic kitchen and bathroom facilities, but was sufficient to our needs, with a very comfortable double bed, and two lovely little balconies giving a bird's-eye view of the bustling Rue de Clignancourt.
Local facilities are good (though some directions to the local Carrefour supermarket would have been helpful) with countless cafés, an excellent patisserie virtually outside the front door, good wine shops, as well as (inexplicably but amusingly) many many wedding shops! :)
Sacré Coeur is literally round the corner, and Barbés Rochechouart Metro is only a five minute walk (Château Rouge, which I believe is even closer, was closed during our stay). The taxi with luggage to Gare du Nord only cost 7 Euros.
The six flights of stairs (no lift) keep you fit, but the view from the balcony is worth it. A charming Parisian hideaway in the vibrant Montmartre district. Thank you Vladimir.