The good things:
Great location with easy access to the Metro, restaurants, groceries, etc. There is a mini grocery store next door that has pretty much everything you need and there are two bakeries on the block with excellent pastries for the morning. The Metro is just two blocks away and it's easy to walk to areas like Le Marais and the Pompidou Center.
Beautiful space, although a bit smaller than how it looks in the pictures. The general spaces where we can all gather is a great size for a big group. The bathrooms are really tiny, but that's somewhat to be expected for the city. They are situated in an unusual way - there are two toilet rooms and three bathrooms with showers and sinks. Overall great size for a city apartment though.
Very clean and well-decorated.
Has pretty much everything you need in the kitchen, although we didn't cook much.
The frustrating things:
The apartment is located on an incredibly busy street and 3 of the 4 bedrooms are located on the street-side. It's necessary to keep the windows open for the air, but the noise was so loud all night long that it was difficult to sleep. There was also construction happening next door which resulted in a lot of dust and noise in the apartment.
The owner does not provide any of the basics - no hand soap, dish soap, paper towels, toilet paper (except what's on the roles), etc. You know that people leave stuff behind, but they obviously clean it all out before anyone arrives. We had to buy basics that really should just be there.
Check-in did not go as planned. The person who was meeting us to let us in was over an hour late.
When we tried to use the dryer, it kept cutting off the electricity and we had to flip the fuse switches. We couldn't be running anything else - like fans - if we wanted to use the dryer.
Two of the three shower heads didn't work right. They were supposed to be rain showers, but they obviously weren't connected right and the water poured out over the top of the shower head instead of coming down through the rain feature part.
Overall, a great location, a nice size apartment for the city, very clean and well-decorated, easy access to what the city has to offer. Just a few frustrations that could be easily fixed to make this a 5-star experience.