My husband and I came to Paris for two weeks on our honeymoon and stayed in Marco's Art Flat the whole time. We couldn't be happier with our choice of home base for our romantic vacation!
First of all, it's super centrally located, in the heart of Le Marais. Take a short walk in any direction, and you'll reach a ton of great boutiques ($$$$ though!), a large dept. store (Le BHV/Marais) and a number of cafes, restaurants and places to pick up groceries. You are less than a 10-minute walk from three Metro stops and are surrounded by Velib bike docks (which range in availability depending on day and time), which we used A LOT.
The Eiffel Tower is a tad far; we biked there one night, and it took just shy of a half-hour (and a decent work out). But really, anywhere in the city is super accessible from this place (by foot, bike and/or Metro).
The flat is up 3 flights of winding stairs with no elevator. It was a bit tiring with our luggage, but after a couple days, we got used to taking them up/down every day. The place has everything you need—AC, heater, fireplace, reliable WiFi, shower (no tub), espresso machine, microwave, stove (induction!), oven, dishwasher, fridge, washer/dryer, closet, queen bed (a tad on the firm side and a European queen...it's 2 inches wider than an American queen, I think). The kitchen is extremely compact but fully (and well) equipped. We cooked a couple nights, and as long as two aren't trying to do so at once, you're fine! :)
The flat is across the street from a playground/park as well as a church. The church does ring its bells every day; the earliest we heard them is around 8am, though we found them totally easy to sleep through/ignore. In the evening, people do tend to hang out on the church steps. Though their sounds were like the church bells—pretty easy to tune out (for us, anyway).
Marco provides a thorough house manual and is easily reachable should you need him for any reason. And the photos above very accurately represent this beautiful space. Bottom line, just book it, already! :)