Lucas' place is in a great location for main Paris access (very near to a Metro stop and quite central), and his neighborhood has a selection of diverse restaurants and charming bakeries. We felt very safe.
The space itself is a bit tight, specifically in the kitchen / bathroom areas. It *IS* listed as a studio, after all, so don't plan on doing much cooking (plus, it's Paris - there are so many delicious things to eat in the city!) It was a good space for 2x to share, knowing that we spent most of our time outside touring. To its benefit, the main sitting area has plenty of good space for relaxing and hanging out.
The apartment was very clean and organized when we arrived, and Lucas took special care to come collect us from the Metro station. He gave great directions, had good advice, and made sure we were equipped with what we needed for a nice weekend. He was very quick to respond, and we enjoyed chatting with him.