I arrived at the Hotel Mamiani only to be told that my room, which had been booked for well over 3 weeks had been given away to another guest and there was no room for me there. Instead, the concierge booked me into a sister hotel called The Osimar which was well out of the heart of Rome but he told me he would pay the taxi fare for me to get there. When I protested that I didn't want to spend the weekend so far away from the major attractions I was simply told that the concierge himself travels one and a half hours each day to get to Rome and that Rome is a big city. While he apologised to me I could tell he was merely waiting for the taxi to arrive and take me out of his sight.

I got into the taxi and with a little help from my husband promptly booked myself another room in a Roman hotel I had stayed in the year previously. The entire experience was extremely stressful and I am thankful that it was not my first time in Rome therefore was able to tell how far the Hotel Osimar was from where I wanted to be and also was able to call another hotel and book myself into it.

I can thoroughly recommend Mamiani hotel.
We stayed there for a week-end in Rome in January.
We booked a triple room and have been very pleased with the experience. Location is good, within walking distance of the railways, and even closer to a metro station. The room we had was very clean. The decor was basic but we did not expect much for this price. There was TV with satellite channels (all in italian), air-con, hair drier, mini bar, safe and en suite shower/toilette.
They accept credit cards, and it's better to book through one of tripadvisor's recommended website than direct, 70 Euros vs 110 Euros.
The staff at the door was very friendly, even though their english is not very good. On the downside, the hotel is not very visible from the street, you have to know the exact adress to find it. An other negative point is that the walls are quite thin and you can clearly hear the party goers coming back to the hotel in the early morning.
I would definitely stay there again.