I stayed at the Relais Bosquet with my daughter in January 2008. It is a beautiful hotel in a quiet, charming neighborhood. While the room was small by American standards, it was no smaller than places I have stayed in London and the bathroom was so beautiful and well-appointed (much nicer than the London hotels' bathrooms, which were about 2 feet square) that it made up for the smallish room, in my opinion.
We never had their breakfast buffet, which offered a wide selection and was beautifully served, because it was €20 each. Like many other guests, we kept yogurt and fruit in the room's refrigerator, made tea with the supplied kettle and complimentary teas, and frequented the neighborhood boulangeries and cafes.
The staff was wonderful: respectfully friendly and very helpful.
There are two free internet computers in the lobby, where you can also read a variety of international newspapers and magazines. A feature I really appreciated was the free wifi in the room! (I came to Paris from Berlin, where I had had to pay €15 a day for internet access in my hotel room.) I wasn't able to print my boarding pass in the hotel, but there was an internet cafe just the other side of the Rue de Bosquet, also on rue Champs de Mars, where I could.
We had a car when we arrived and I was able to use a hotel-arranged space in the underground parking lot by the l'Ecole Militaire metro station at a reduced rate (€20 a day, rather than €25 or more.)
The location was perfect for us, since my daughter was enrolling at the American University in Paris, located just blocks away. The metro stop for l'Ecole Militaire is very close. The Eiffel Tower is a short walk away, as is the Seine. We walked to Notre Dame in 35 minutes.
I think the Relais Bosquet was the perfect pied a terre from which to become acquainted with Paris and I plan to stay there again on future visits, of which I am sure there will be many because I don't think my daughter will ever want to leave Paris.