Preliminary comment-although I gave a 4 star rating, with a few changes it would be a 5+, and in all cases even without the changes I would return to this same place again on my next trip.
The good:
The location is absolutely perfect: near several metro stops on different lines such that from one or another of these stops you can get almost anywhere in Paris without having to change trains.
The neighborhood itself is very non-touristy, and within 3 blocks you will find several excellent boulangeries/patisseries, several produce markets, a small supermarket (which is in the same block as the flat), a few pharmacies, a great butcher shop (which has rotisserie chicken all day), dozens of restaurants/bistros/brasseries of varying cuisines and price points, a chocolate shop, an awesome cheese shop, a couple of wine stores and much much more. Within a not unreasonable walking distance is the Luxembourg Gardens and the more touristy hubbub of the Montparnasse area.
The flat itself is roomy, it has a living room over the Rue de Sevres, which is somewhat of a noisy street although we kept one of the two windows opened during our entire stay because the air was so nice; the bedroom is in the back with a window over the interior courtyard and it is quiet back there.
The kitchen does have a refrigerator/freezer, microwave, washing machine (as is typical for Parisian apartments, there is no dryer but there is a large drying rack, and there is a laundromat around the corner where we went to use the dryer after we'd washed our clothes in the flat), dishwasher, and a "capsule" type coffeemaker.
WIFI worked well during our stay.
Now the reasons for the 4 stars instead of 5 (which individually could sound petty but on a cumulative basis they add up):
--the bed is comfortable, but is essentially on the floor, I wish it had a frame and was up higher
--advertised amenities include extra pillows and blankets but we didn't see extra blankets (we didn't need any anyway) and there were only 2 relatively thin pillows (I don't know about others but I like having a few extra pillows for sitting up and reading in bed and I typically sleep with a fatter pillow (or two thin pillows) under my head); there were no extra sheets.
--there are no nightstands next to the bed, there was a cardboard box on one side that seemed to serve as a nightstand but that was it
--of the 3 large windows in the flat only 1 (one of the windows in the living room) would open; the other living room window was hopelessly stuck closed and the window in the bedroom will only open a few inches as the curtain rod obstructs it
--the towels were not very big and were really thin and there were only 3-4 of them
--advertised amenities include shampoo but there was no shampoo in the shower, just a partially used bar of soap
--the kitchen was pretty poorly equipped in terms of utensils, the only thing sharp enough to cut fruit was a small serrated bread knife, luckily we had brought a couple of knives with us for picnics etc. and we were able to use those to cut salami/cheese etc.
--the night we decided to to laundry we found that there was no laundry detergent so we had to run out and buy some (luckily there's the supermarket just down the block)
--there were only 4-5 coffee capsules when we got there for our 5 night stay so we had to buy more of those immediately (again, nearby supermarket is very handy)
--although we didn't eat in much and did very few dishes, the dishsoap that was there barely lasted until we left
In a nutshell--as I said up top, I would stay here again even if nothing changed, because the location/neighborhood/apartment size are perfect for me and I can adapt to all of the items listed above. I just wanted to give an honest review so that others who choose to stay at this flat will know what to expect.