If you're looking for a great spot to stay in Paris, then I guess staying at Juliette is a great place to start with. The location is central , just under the majestic Pantheon from where you can reach the Boulevard St Germain in two minutes and do whatever inspires you. The place is tidy and clean. You'll have your own bathroom and all amenities for a cosy stay.
The family lives just above and so, if you have any question the mother of Juliette will show up and help you.
I strongly recommend