Afifa's apartment was perfect for my 4 night stay in Paris.
I've been to Paris many times, and I like this area best (where The Marais, Oberkampf, and Republique meet) for many reasons (easy to get to from Gare du Nord/Gare de l'Est/CDG; easy to get other places in the city via walking, Metro, or bus; many places to eat and drink; many "amenities" (specialty shops, laundry, etc); not in the middle of St Germain; etc). This apartment is a great location meeting all those criteria.
It's on a safe, side street. It has very good security. It's on a higher floor so it's very quiet. It has a stylish "rustic + modern" design. It is simple but very comfortable. It has very modern "fixtures" (hot water/stove/heating/etc). The kitchen is great for small meals (there isn't a dining table, but there's a nice counter with barstools). Grab some fresh ingredients at Marché Popincourt and eat in one night, you won't regret it!
Some things to be aware of:
You will have to go up several flights of spiral wood stairs with luggage if you stay here.
There are some motion-sensing lights in the building but sometimes they don't work. It is _very dark_ in these areas at night. Have your phone flashlight ready!
The bedroom, sink, toilet, and shower are essentially one room. I was alone but I could see that being a little "crowded" for 2 people. However, there's a pocket door to separate the shower/toilet space from the sink/bed space and a door to separate the "bedroom" from the rest of the apartment.
The Metros 3, 5, 8, 9, and 11 are all close, plus Bus 96, the best bus in the city!
And within one block: Chez Imogène (crepes from Normandie), a laundrette, a Franprix (supermarket), Petit Bleu (last minute gifts), Utopie (Boulangerie Patisserie), and too many cafes to name.