Joel's place is absolutely perfect for a trip to Paris! The location is amazing, it's right in the middle of Pigalle, about a two-minute walk from the Moulin Rouge and near to loads of great bars and restaurants. It's super close to the metro, and walking distance from the Gare du Nord which is handy if you've taken the Eurostar.
The area is definitely safe – it's close to the Moulin Rouge, so there are a lot of themed shops nearby, but it just felt to me like being in Soho in London – it's very touristy, but it's not a "bad neighbourhood" at all. We felt totally safe going back there late at night after a few drinks and we were two girls alone.
The flat itself is really nice, there's a main bedroom with a second sofa-bed in the living room and a fully equipped kitchen. Plus, the place has balconies that look out over the main road, which are great for people watching and taking in the views. Finding the place and checking in and out was really easy too, Joel sent over all the instructions we needed, and he was super responsive during our stay if we had questions.
It's a great, great place – I can't recommend it enough!