For sure it is highly convenient to have a metro stop right outside of the door of your apartment building- that fact, along with the Marais district being fairly central in Paris - makes this place a solid location but the area right around the building has some people hanging around for various reasons (selling street corn, there is an atm close by, etc) but it does require you to be 'aware' of your surroundings.
The rooms are very small - the angling of the photos make them look much bigger than they actually are. And therefore, there is barely room to open the windows - in fact, you can't open one of the windows without moving the bed away from the wall (in the room with 2 beds). And in this age of global warming- the cross winds would have been really nice.
Overall, our stay was fine and dandy and communication with hosts is fast and helpful.