The apartment is beautiful and tastefully decorated, although compact it feels spacious because of the floor to ceiling windows and general height. The sofa bed in the living area was perfect for my 2 teenagers to have their own space and apparently very comfy.
As other reviews have mentioned there is only one toilet downstairs. The stairs and floor are creaky so you cannot go quietly in the middle of the night! However the floor is beautiful and worthy of the odd creak.
The apartment is very well positioned for a short walk to the Metro, and surrounded by plenty of shops and bars/restaurants with a lovely atmosphere in the evenings. There are small supermarkets and a market nearby to buy the basics.
Marais is a lovely area to spend time in Paris, and we would thoroughly recommend the apartment for a great base to stay.