After reading what felt like a million reviews and being mindful of our budget we ended up staying at Hotel Zara. Located extremely close to Republicca Metro stop, about 10 minute walk from Trevi Fountain and in a great, safe location near Via Nazionale.
We were a group of 4 adults and decided, to save on money shared a quad room. Like most European hotels, double beds are made of two single pushed together. When we arrived, the room was split into one double, two singles which was easily rectified by moving the two singles together and rearranging the side tables. We didn't bother the staff with this when we could do it ourselves. It wasn't hard. The room itself, after having read many reviews, we were expecting very tiny with barely any room to move - so when we walked in to our room we were pleasantly surprised by space! There was enough for the 2 double beds, 2 small side tables, a desk, a luggage rack and 2 door wardrobe with ensuite bathroom (bath, shower overhead and toilet and bidet). There was plenty of room to walk in between - it's not a suite at the Hilton but for the price we paid (booked directly through the hotel website at quad room rate, 129 euro per night) we were happy enough.
Cleanliness - the room was made up daily and hotel toiletries (small soap and sachets of shower gel) were restocked daily in abundance. The bathroom did have a damp smell to it - to be expected when there was no window in the bathroom and the only way of drying it was when the light was on and the extractor fan kicked in. There was only one bin (in the bathroom) for the room. Like most European hotels, there is no in room coffee/tea making facilities and as a seasoned traveller, we own a small travel kettle so could make coffee in the room (I bought along our own coffee and purchased milk from a store nearby).
Light - some of the other reviews have commented on how dark the rooms are. I agree. Light was provided by 3 wall lamps (no overhead main light) and during dusk hours, it made the room dark (the time when you might come back from sightseeing and want to freshen up on the way to dinner) but, given that we weren't spending a lot of time in the room, this was a minor inconvenience.
Heating - we went in April (spring in Europe) and had very pleasant temperatures while we were there (20 degrees celsius plus, fine sunny days) and the room subsequently was a bit stuffy. You could open the windows in the main room (where beds etc) were but it was a bit stifling at times. There was an air conditioning unit but when I asked reception how to work it, they said "It doesn't get turned on till 1st June" - they assured us it was safe to sleep with the windows open and, after looking out the window and discovered that it would take spiderman to enter the room, we left the window open at night and were much much cooler this way. There was a radiator in the room and thankfully, for this time of year, it wasn't on!
Breakfast - breakfast was included (which I wasn't aware when we booked!). Typical of some European countries, it consisted of lots of pastries, bread rolls, jams etc (no ham/meats though) and 2 different cereals plus a free tea/coffee machine. For something we weren't expecting, this was fantastic. It was enought to keep us going! We didn't eat in the dining room so not sure about this.
Overall, it's a clean enough, safe enough hotel in a great location at a great price. It's pleasantly decorated. It's not luxurious but when we go away on holiday, we don't spend a lot of time in the room so it suited our needs perfectly! The reception staff were very helpful - giving us maps, helping us with Metro stops for the Vatican and booking us a car service to take us back to the airport (which worked out the same price as catching the train for 4 of us)
Just a note - there was an additional tax to pay upon checkout of 24 euros "preferably in cash" - I have no idea what this was but for 3 nights incl this tax, our stay was still under 400 euros.
Rome additional comments - we got a lot of use out of the Roma Pass (available for 25 euros at the airport) - it covered our entry into the Colesseum as well as lots of other areas it either gives you free or discounted entry but we got most value out of it on the Metro (tube/subway) system. It fast tracks your entry so no long queues at the Colesseum ( a huge bonus).
The Metro system is very easy to use and the best way we got to main attractions but the city is quite small and very easy to walk around.
Food in general is quite expensive and we found the local supermarket "DeSpar" was right around the corner of our hotel and we stocked up on fruit, water and the amazing "pocket coffees", crisps, chocolate etc here for our day trips and tried to limit eating out to night time meals only. Restaurants right near major tourist attractions are VERY expensive so be warned! Try walking up the smaller alley ways away from the attraction and you'll notice the prices start to go down. There is a fantastic restaurant around the corner from Hotel Zara on Via Nazionale, next door to DeSpar supermarket that had very reasonable prices and great staff and fantastic food (including an incredibly fresh whole oven baked sea bass).
Be mindful of people trying to sell you things - you may be given a rose by a seller (usually Indian origin) and then they expect money. If you refuse, they get offended and hang around you till you either walk away or get assertive. I handed a rose back after being given one and had the rose flicked at me - quite an aggressive gesture I thought. So just be careful. They're not all nice! Also - take precautions with your belongings - it's interesting to just watch the sellers when you're sitting down eating - there are a lot of street sellers that also eye off your bags so keep them close at all times and don't get huge wads of money out!
Hope this all helps!