Stayed at this awesome little hotel with the gf on a weekend break after some TripAdvisor research for somewhere cool and fun to stay in Paris. Hotel came very highly recommended and didn't disappoint... Opted for a Superior room, and, although have no comparison, felt like the right decision to make as it was perfect. We were on the top floor, with a great balcony and a room that felt ideally sized for everything you need it to be on a weekend in this beautiful part of Paris.
Staff were always super friendly and helpful at all times of the day/night (bowls of ice for late night Rose drinking sessions a definite bonus). Also, on first night they managed to source us some Moulin Rouge tickets at very late notice with nothing more than one phone call from the room, which turned out to be AMAZING!!! If you've not been, then JUST GO, its walking distance and one of the best things I've ever seen...
Hotel is great for all the reasons everyone else has mentioned a bunch of times below (atmosphere, decor, snacks and drinks all day etc), but more than anything we really just loved the location. Felt like you were away from all the overtly touristy parts, that we didn't end up missing at all. Great little resto just down the street, and enough other cool bars and bistros to mean that we got nowhere near exhausting the surrounding streets in (our many) lazier moments. Also super easy to get around with metro tho, and a pretty enjoyable walk down to river and main sights and stuff if feeling like a wander.
Make sure you check out Sacre Coeur as well if at a lose end on a nice evening. Grab a couple bottles of Rose and you wont be disappointed after the walk up. There was a whole chilled vibe up there the Saturday we went and just sat on the steps listening to a guy playing guitar and watching the sun-set over the City...pretty special!!
So yup, in short, this place is awesome. Great location, perfect little hotel, and good times all round. We made a promise we'd come back every year and fully plan to stand by that!