I stayed at the Hotel de l'Opera (~2012) and i had a great stay, however i did stay in one of their nicer suites. Its basically opposite the Metropole and if you can snag Accor Platinum status you might get some sort of room upgrade. My room wasnt dated, if anything it was a little outrageous from memory (think zebra prints, mirror finishes, gold taps), and the breakfast that we had included was half decent for a hotel breakfast. There was a nice bakery nearby selling Parisian style treats too. We didnt spend alot of time in the hotel as the areas both north toward the old town and lake and south toward the more non touristy areas were filled with great local style cafes and places to eat (we love street food). Our view could have been skewed by the very low price we paid (i think it was close to ~$120USD but AUD was around parity or better), and the room was massive, great view, some sort of lounge access for coughtails, breaky included etc.
The metropole definitely has that foreign correspondents / colonial vibe going but it seemed fairly contrived and crowded. I didnt find the common areas to be as nice as say the Raffles (sing) or Peninsula (HK) etc.