Carla's apartment is simply excellent. We were there for ten weeks as part of my sabbatical. I summarize here the main points:
1. Location, location, location. I simply love this area. It's also close to where I go to work, but we simply love it. Carla's apartment is across the street from Parc Montsouris, which we also love. (We can also recommend the Bistro in it.) You're close to the RER B (Cite Universitaire), the Metro (Glaciere for the line 6, and Alessia for the 4), the tram T3a (which takes you all the way to the stadium for PSG), and the buses 21, 88, and 216. You're very well connected. But what we love the most is that it's a very residential area. There are basically no tourist around, and you still can walk to the Butte aux Cailles neighborhood, which we also recommend.
2. Space. We picked her apartment because it has plenty of space. There's a living room with two couches, a separate dining room with a table for six, then kitchen, bedroom and bathroom. (Just for completeness, I don't like the separate tiny room for the toilet because they tend to be on the smaller side. But this is a common feature in Paris.) I could work from home, while my wife could browse, or watch tv via the router. The wi-fi was excellent. Only spotty some times at night, but not very often. The apartment has everything, oven, washer and drier, etc. The drier is separate from the washer. It's not one of those 2-in-1. For us this was great. (We stay more than two months, so being able to do laundry was a big plus.) The apartment also has lots and lots of light. The two large windows face the Parc. (It's a second floor.) The bathroom with the shower is new. The shower is great. (I like a healthy stream of water!) The photos are accurate. The only difference is that Carla bought new (blue) couches instead of the white ones in the photos. Ah, there's also an extra storage space, which was very convenient for us. There's basically an extra large closet and plenty of room for suitcases, etc.
3. Communications. Alex (who manages the apartment for Carla) responds right away to our texts. We only needed to contact him during our stay to know how to turn on the heating. (We arrived when there was no need.) And basically only to check-in and check-out because we never had any issues.
4. Misc. We found the apartment very clean. As I mentioned, it's on a second floor and there's a small elevator (basically fits a person with a bag, or two people). There are two bakeries one block away, and they nicely complement each other. One opens on Sundays and the other one opens on Mondays.
I visit Paris at least once a year, and I can tell you that I'll be back at Carla's apartment.