My wife and I travel internationally every year and this hotel is definitely not a 4-star hotel. We've stayed in 3-star hotels that have far exceeded our experiences here.
Let me start with what was good: 1) the staff is courteous and responsive, 2) the free breakfast was quite satisfactory, and 3) the Pantheon is just a block and a half away. Now...the rest of our experience.
Finding the hotel can be a challenge if you don't know where you are going. It is very non-descript and, if you miss the small sign next to the door or you are not paying attention the address numbers, you can easily pass it by.
The check-in lobby is quite bit small. If more than 3 couples are checking in, you'll need to wait in the entry hallway. There was 1 small bench in the hallway. Larger groups will easily "clobber" the lobby. We were offered a complimentary espresso while checking (from a Nespresso machine in a small plastic cup) and a pastry.
Overall the hotel has a dingy and run-down appearance (as noted in some of the photos). I don't know if things were better in the past and they got worse over time, or if past renovations simply weren't up to par from the beginning. Much of the renovation construction we saw in our room (trim, plumbing, electrical, etc.) would not have passed code or inspection here in the United States. We poked our nose into some of the other rooms and the large suites seemed to be of a higher quality, but a true 4-star hotel will have a consistent quality throughout, not just in "premium" rooms.
Perhaps room 307, where we stayed, is their lowest quality room, but if other rooms have similar conditions, the quality of this hotel can easily be exceeded by a Motel-6 in the U.S. All of the walls had luggage scuff marks. The furniture was low-budget Ikea-quality. The armoire was falling apart. The legs on the nightstand were loose and wobbly. There was no phone in the room so you must go down to the lobby or the 1st floor bar/dining area for any services. Towels were stacked on a table in the room because there was nowhere in the small bathroom to hang/store them. There was no facial tissue anywhere in the room and my wife had to go down to the lobby to ask for it. Several lights were burnt out (1 in the bathroom and one in the room). There was an odor of mildew coming from the air conditioner. The various required signage on the back of the door was Scotch taped to it. The light over the sink looks like one from a night stand. It provided very poor "task lighting" for things like shaving or putting on makeup and, if you were taller than about 5' 10", you had to look around it to see yourself in the mirror. The mini-fridge was room temperature. I think it may have been on the same circuit as the lights, which will automatically go off if you don't leave a key in the light switch. It didn't get remotely cool until mid-day on the second day of our stay.
I'm not sure where the sound came from, but there is what I would describe as a faint and distant fog horn sound that repeated every 5-6 seconds. It was unnoticeable during the day, but I could hear it throughout the night and it made for a less than restful evening (at least for me).
The housekeeping staff could be found each morning lounging in the 3rd floor "library" waiting to begin their daily work. A 4-star hotel does not have staff lounging in client spaces. They also would stage all of their cleaning equipment and supplies in the hallways (bags of linens, vacuum cleaners, etc.)
The front desk closes up between 10:00 p.m. and 7:00 a.m. so you are pretty much on your own between these hours (again, not something a 4-star hotel does...even Motel-6 "leaves the light on for you"). There is an emergency number you can call though. You are issued several pass codes, 1 for the front door, 1 for access to your floor once you are inside the hotel, and 1 that I can't remember (I think it was for the elevator). If you lose or forget those codes, you are out of luck.
The terrace was nothing to write home about. If you want drinks or snacks, you'll need to go down to the 1st floor bar/dining area to order them, but they will be brought up to you. Room service is available but, without a phone in the room, you need to go ask for it.
Overall it was a very disappointing experience. We won't be coming back to the Terrace Pantheon Relais and we're not recommending it to others. Definitely NOT a 4-star hotel.
