The location is fantastic and it's a great little hotel. 3 stars seems harsh, it seems comparable to many 4 star in Paris. Stroll out of the hotel to the hustling streets with cafes and restaurants everywhere. I was there for work but my wife joined me for the weekend too and it was excellent. We spent a couple of days wandering Paris. It was during the transport strikes so we walked everywhere (as far as the Eiffel tower) but we would have done that anyway. Breakfast was good, although you could easily get it for around the same price or less at any number of cafes nearby.
Rooms are a decent size for Paris. i.e tiny but manageable. The shower was a little cramped with just a shower curtain to try to stop the inevitable leaking. The only real gripe I had was the two single beds pushed together for a double wasn't great as they kept splitting apart with a big dip in the middle. Not great for the romantic Paris experience if you get my drift. Overall though, very happy with the stay and one gentleman staff member was especially friendly and helpful.