Nice central location, with short walk to several metro lines, and for the hardy, 20-30 minutes walk to the Louvre, Montmartre, or Champs Elysees. Good Monoprix supermarket across the street, and next to the high-end shopping district. Front desk staff is friendly and efficient, and housekeeping staff is faithful about emptying trash and re-supplying towels daily. Our suite for three was reasonably spacious, with sitting area / extra bed on the lower level, and main bedroom in a loft up a spiral staircase, and two toilets and two sinks so no waiting. Kitchen space is too small for serious cooking, but large enough to prepare coffee and light breakfast.
A few quirks -- none of the ventilation fans in the bathroom spaces seemed to work (zero for three); and hangers in the closets were depleted -- we had a total of about four in the suite. Wifi is unsecured captive portal type, so you need your own VPN to use it securely, and it was sometimes flaky, dropping out and requiring re-connection every ten minutes at certain times of the day.
The hotel is located at the intersection of a very quiet dead-end street and a pedestrian-only street with small plaza, so it's very quiet overall. It also attracts a half-dozen guys who sleep rough in the plaza. They tend to use an alcove just east of the hotel as their urinal, so the aromas on Rou Joubert are sometimes challenging. Some of the guys also seem to have "mental health challenges" so it pays to be aware on Rue de Caumartin.