We had a very nice stay at Régine's apartment. My parents and I loved it. The apartment has a nice kitchen, living room with nice view (the sofa where I was sleeping is very comfortable), very good bathroom with good shower, bedroom with good bed and beautiful view of the streets.
The temperature of the apartment is perfect, there is no noise in the streets during the night. The building also has elevator to the 4th floor.The neighbourhood is calm and safe.
The Marais area couldn't be better. The square in front of the building has everything you need: a delicious bakery on the corner and a very nice supermarket (Monoprix) where you can buy good food and very good and cheap wine.
Republic's place and metro are very near too. It's easy and fast to go everywhere.
Régine is a very nice and lovely person and always gives you nice tips for what you need.
I sure recommend you to stay there!