Great two bedroom, two bath apartment on a quiet street but within meters of great restaurants, bars, wine shops, and essential shopping. And both bedrooms have AIR CONDITIONERS and we needed them too. The apartment is well laid out so that both bedrooms have privacy. Everything we needed was already there. There was a G20 grocery store within 400 meters where we could stock up on everything else we needed. There was a bakery on the corner where you could get fresh bread, quiches, sandwiches etc.
As described, the apartment is one floor up (no elevator) but the stairs were wide, gentle spiral stairs so it was easy to get up and down. The living room/dining room is large by Paris apartment standards and provided plenty of room for the four of us to sit and visit or to eat. The apartment had a laptop although we did not use it. There were ample places to plug in and charge your equipment. Just remember to bring your plug adapters if you are not from Europe.
Le Marais is a great place to stay and I don't thing you could find a better apartment in the entire area. And the cost was very reasonable for the accommodations. We would have needed two hotel rooms to accommodate us and we would have had less space for more than double the cost. This is your place. It certainly was perfect for us.