Cozy and clean little apartment with great accessibility - 6 different metro lines within 10 minutes walking distance. It's also pretty close to city centre, just 5 metro stops to Chatelet, which is just across the bridge from Notre-Dame. And there are many different shops, stores, bars, cafés and restaurants in the streets around the flat.
We haven't actually met our host, just one of her friends who gave us keys, but they were both helpful, welcoming and keeping in touch through texts and airbnb chat.
TL;DR: Great place for a young couple on romantic Paris getaway.