Great apartment in a very central place, close to quite a few metro stations. Very spacious, quiet and well equipped. Clausis is a great host, very sweet, polite and responsive - and we resorted to her help quite a few times!
A few minor suggestions for improvement (given the longterm stay requirement) would be:
a) an extra set of linen and towels (one can wash & dry the existing set in the same day but it would help to have a spare one given it's not advisable to use the laundry past 8pm ~ drying can take up to 3,5h),
b) better lightning in the bedroom - the lights are lovely for reading but not great to find out if you're wearing black or bleu marine :)
c) new bed mattress; you can tell it was once very comfy and good quality but a new one would go a long way. I guess it's the normal "wear and tear" as with all things :)
d) would be great to highlight the absence of an elevator (frequent in quite a few buildings in Paris) in the specs of the listing so that people with motor disabilities - or temporary injuries - can take it into account before booking. We didn't mind as it's only 3 floors up but had a hard time with our suitcases.
Even with the above areas of improvement, our stay was great!