The entry level rooms are not up to par, not even space for bedside tables. Suites on the other hand are good and well appointed. It is a very low key, discreet hotel. The location can't be beat. Breakfast is very basic but good - but they have limited tables so there may be a short wait. The honor bar is a nice touch.
I didn't find the service very warm or friendly, or going a bit beyond the expected. I was eligible for an upgrade but was never offered one though rooms were available (found this out later). Dinner recommendations were not appropriate (formal when I asked for casual).
Despite that, I'd recommend it if you don't want glitz, want to be in the best location in Paris, and book a suite.