The tl;dr version is that the flat is bright and warm, and in a fantastic location. Definitely a great place to stay for "living like a local."

The longer version:
When we showed up, we were given a thorough tour of the loft, and were made sure that we knew how to use everything, including the wifi.

The building itself is extremely safe, as there are two passcodes required just to get into the inner courtyard. The loft's door has a complex deadbolt, making it very safe from the inside.

We instantly noticed how bright the space was, which would be perfect for a summer getaway. The giant windows allow easy views out into the street, but were also easily closed for privacy. The upstairs section of the loft is very cozy.

The location is fantastic, being right next to the Pompidou Center, and near amazing restaurants, both French and international. (There's an amazing macaron store down the street called Monsieur Benjamin!) It is also within a short walk of the Metro system, making it easily accessible to anywhere else in the city, and within 15 walking minutes of the Louvre.

Overall, we were very satisfied with the flat, and would rent this space again.