Here is a summary of what we experienced in this self-acclaimed “4-stars hotel”, at a double-bedroom rate of EUR 250,- per night:
. We arrived last Friday, at around 6pm. No one around to open the front door. After some 5 minutes of bell-ringing, and door-banging, a young man squirreled around the corner, to open the street door, and to let us in. No welcome, no help with the luggage, which we dragged to the first floor (as there is no elevator).
. The next 10 minutes are spent in a lengthy discussion about which room should be available for us. We were expected to relocate to a “second “place, Via Banco S. Spirito, of which we knew nothing. We declined, and insisted to stay at the place we booked for.
. We are then given Room #102, which is far below everything we had expected from a “4-star hotel”: smallish, modestly furnished, with 1 chair only (for a couple !), the bathroom is 1.5x 1.5m-sized, and maybe OK for 1 person, impossible for 2 (you have to open the sliding door of your shower to be able to use the toilet).
. No-one around all day, only a few booklets and leaflets are spread out for information.
. The hotel sits on top of a bar below, with nightly “music sessions”, right until 2am, making sure you are kept awake for your “entertainment”.

The hotel is an old building and there is only so much you can do with that, it was very clean, the staff were extremely helpful, internet was free, you could use a lounge room to use their computer and printer, and also a nice area to chill out and read a book, although the hotel is more a place to sleep. The bathroom was cramped, but modern and everything worked.
The breakfast was plentyfull, the lady working there efficient, but a slight lack of tables at 9.00 a.m. when everyone decided to be there at the same time during the period we were there.
No outside noises, which is amazing for the amount of activity outside on the main square.
Would definetely recommend this hotel because of it's ideal location and ample facilities.

As shown by the rating we were very pleased with our stay at Casa de' Fiori. Except that in spite of its name it was not the hotel we had expected.

From the hotel's name, address and description it appears as a hotel located at the corner of Campo de' Fiori. The "mother-hotel" is, but Casa de' Fiori are two physically separate hotels. The second (where we stayed) is fantastically located on Via Banco di Santo Spirito, a few meters from the Ponte Sant'Angelo - but this "detail" of approx. one kilometer can be deduced only from the name of the room type - nowhere it is told that there are two different hotels with the same owner and same name.

This problem was common to most of the guests we met at Via Banco di Santo Spirito location of the hotel.

Both hotels have the same standard, but you must be aware of this problem if it matters to you whether you will be staying at Campo de' Fiori or at Castel Sant'Angelo.

Watch out that you are not placed in the "satellite" of the hotel! We booked a room at the hotel Via de Biscione, and all data printed said that we would be at Via Del Biscione 83, 0 km from Campo de Fiori, where we indeed wanted to stay. However we were placed to via Banco S Spirito 52 close to Vatican, several blocks from Campo de Fiori. When we reclaimed of this, we were asked to see the "room description", where with small fonts was named this adress of this satellite room. we had clicked the "show your hotel in the map", and it had said that we would be at main hotel at Via Del Biscione. The room proce was same, and the service very bad. The breakfast maid was late on both mornings, when we were to go for the airport Saturday morning at 9.00 and Sunday morning at 8.00 was too early to the young lady!