We (2 persons) booked a double room for four nights after reading the reviews here at trip advisor, and we were not disappointed. The service was very familial, the room was clean, fresh and cosy with a slight romantic touch. Perfect for a couple. It's located in a typical hotel area next to the train station Termini. We could reach all major tourist attractions in Rome by foot without problems, although we took the subway to the Vatican, (just a couple of stations away, takes about 10 minutes). The breakfast was mediterranean standard, good enough for us! Altogether, a great little hotel I would highly recommend.
Note that Google Maps currently shows the wrong location. (It shows the location of Hotel Europa) Domus Praetoria is located on Via Milazzo, next to Termini. Follow the street down to the last block, til you see Hotel Gabriella, and the hotel is on the left, by a rather anonymous door. Have a good trip!