After reading most of the reviews before travelling and booking this hotel, I was somewhat scared but took the decision of giving it a try. I was pleasantly surprised!!! What’s more, I stayed twice at Adas Hotel, in February and in July this year. It is a very cheap hotel so one must be aware of what to expect.
I don’t agree with other reviewers. Some people seem to expect five-star facilities in a budget hotel. If one likes and enjoys comfort, big spaces, modern facilities, then one must choose another kind of hotels. This is a budget hotel, useful for having a bath and sleeping after a long day in Rome. It is just that! I paid 75 € for a triple room. That is very cheap! Breakfast included! It is true that breakfast is basic (some toast, bread, croissants, jam/butter, cornflakes, milk and the BEST coffee I have ever had in my life!!!).
The hotel has rooms on different floors. The ones that are on the 6th floor are the best ones. Elevator goes to 5th floor only, so if you have heavy luggage, it is an issue. It is an old building (something usual in Europe), with old facilities but its location is perfect! Two blocks away from The Colliseum, about 8 from Termini station, right beside Trajan's Market and the Fori Imperiali, a short walk from Piazza Venezia as well as a short stroll to Santa Maria Maggiore and San Pietro in Vincoli, where Michel Angelo’s Moises is .
It is true what some reviews claim that the hotel is not easy to find (its blue sign is very small) and the stairs “are very dark and unsigned so you are not really sure that you are in the right place”. This is so. However, the address (Via Cavour 233) is easily found, as Via Cavour (full of restaurants and souvenirs shops) is a busy road.
Wi-Fi only in the very small reception area. Friendly staff. Free maps in the reception.
If you are not picky about hotels, but just looking for a bathroom, a bed and a basic breakfast in the Eternal City, ignore all the bad reviews about this hotel!! I would definitely go back! In fact, I did!

the hotel has a very nice staff and 2 kinds of rooms. on the 2 nd floor and 3 rd floor and on the sixth floor. we stayed at first on the 6 th floor. the room was very big and nice. it was a little noisy so we changed it with one on the 3 rd floor. it wasn t on the back side of building but it had 2 sided windows so no noise. the staff changed our room they were very nice. the towels were changed daily, and very clean. i don t undestand the complainers at all. it s a great hotel for a minimum decent stay and great price. indeed the building is very old but that s why rome is great . the breakfast is typical for italiens but for a start of sightseeing is was sufficient. the position is very very good

The only positive aspect of this hotel is that it is really close to subway, Colosseo and Foro Romano. And this is it.
Try not to miss it when coming down the Via Cavour. It's a tiny door and the main desk is not at the ground level.
The elevator is too old and doens't get you through the higher stores. If you're carrying a lot of baggages, big issue.
Bad breakfast and coffee didn't taste good. But this is typical Italy. As a brazilian myself, used to drink great coffee, was a bit disappointed.
Staff not kind. The owner is very greedy or at least that was the impression that we got. Upon our arrival we had already paid 50% and the other 50% would be paid at check out. One day, not our last day there, this guy out of the blue demanded our payment. Kindly I answered that this wasn't what we had agreed and just left.
The bathroom had a leak problem and shower wasn't as easy/comfortable as expected.
And finally, my family called and left a message at the main desk as I was having some issues with my cell phone. I receive the message 36 hours later, after being to the main desk at least twice.

If you're going to spend ALL DAY walking around Rome and returning to the hotel ONLY to sleep this could be an alternative, as it has easy access to subway and some historical points, but be aware of some headache you may get along your stay.

Building: Creepy elevator, size XS, have to use stairs, because elevator goes to 5th floor, and my room mas at 6th.
Room: Changed room because the drain was full of ashtray in the shower, dirty water overflow. But the same pattern of cleanliness on the other room: fungus on bathroom ceilling; used botle and insect fezes on the refrigerator; dust in the curtains, blanket, floor, wardrobe, everywhere; the terrace was an ashtray, full of cigarettes. this is the chamber of death for someone with allergies.
Breakfast: Terrible and unfriendly service, tiny room with poor quality and variety of food. I was served a half eaten croissant, and 3 minutes before brakfast end time, the coffe machine was turned off.
Staff: Unfriendly and unhelpfull
My wife asked for a divorce when she entered the hotel room I choosed because I wanted to save some money, but the RoI was even worse as I had to compensate buying expensive purses to compensate.
Besides all that, the location is great, near the colosseum and metro station.
If you are alone or with a group of male friends and staying near the colosseum is a must, stay in this hotel, otherwise book some hotel more distant and spend 15-20 minutes per day.