Bloss C.
Yelp
I booked at Hotel Nerva for six nights and I was very happy with this hotel:
Rate - I booked a few weeks in advance on the hotels website. I was able to book the cash rate which provided an extra discount, but I did have to have a nice chuck of euros on hand when I checked-in, which turned out to be inconvenient.
Transportation - I booked a car to/from the airport through the hotel which was $50 euros (2 euros more than the taxi flat fare) and I would recommend doing this if you are traveling with luggage like I was. If you are traveling light you can take the Leonardo Express train for much cheaper (8 euro) to Termini Station which is a 20 minute walk or 10 minute taxi to the hotel.
Rooms - I booked the lowest category of room and I was very happy with the accommodation. The room was indeed very small, but this is typical for Europe. What I liked about the room (#201) was it was very clean and it had some nice design touches, and a charming view of a roman ally. I never heard other guests and found the hotel to be very peaceful. I thought the bed was going to be too firm but it turned out not to be; the pillows were too soft for my taste but this was solved by requesting extra pillows.
Staff - Everyone at the hotel was so nice and welcoming. Roberto and Nicole in particular, but everyone was great.
Neighborhood - I loved being so close to a lot of the ancient sites (Colosseo, Palatine Hill, Forum) but not being in a touristy area. Monti has nice restaurant, bars, and cafes very close to the hotel and other sites (Pantheon, Trastevere area, Testaccio Market) were only a 20-30 min walk.
The only downside I can think of was that the safe in the room was small and did not fit my laptop.