This was my first time staying in the Marais district & it was an absolute delight. The flat was fabulous funky, hip & artsy with gorgeous floor to ceiling windows. The kind of place you could imagine someone writing a novel or a famous artist painting his muse late into the evening.
It was huge by Paris standards w a sunken tub & sep walk in shower. Fabulous water pressure which thrilled me! There was even a laundry room which was helpful as I'm currently traveling long term for business.
Like many classic European homes there are a lot of stairs (and no lift) which for me was wonderful (helped me to work off all of the pastries I ate from the boulangerie around the corner) but take caution if you are older or have mobility issues. I happened to be traveling during one of the worst heat waves to strike Paris in 50 years but it cooled down significantly at night & they provided 2 fans so I slept comfortably.
As a single, female traveler I felt 100 percent safe. In the mornings I often saw children dashing off to school in the morning. There are many shops & restaurants nearby. Tip: there is a grocery store just around the corner where I was able to stock up on bottled water & necessities without paying tourist prices.