I would definitely stay here again. Although it can get a little noisy at night from traffic outside, just bring ear plugs and this will be the best sleep you ever have. Rooms are very clean and rooms are nicely decorated and feels more like a home than a hotel room.
Staff can sometimes be bad on directions, but are all very nice and try to be helpful.
Note- During slower times you can negotiate a better rate!

To start off with; it isn't really a hotel but a guest house. Never the less it's a great one. When we arrived the receptionist showed us our room and wanted to know at what time we would like to have breakfast. Next morning we had our personal wake up call with breakfast comming along. This went on al week, we loved it!
The staff is great and are willing to help you with anything.

The building is a very old one; it is so beautifull. A perfect place to go with your partner and everything is on a walking distance away.

Conclusion? -> Just go there and see ;)

We stayed here for 4 nights during the first part of October. The accomodations, though very small, were quite charming. The location is great- just a short walk to the Vatican and still within walking distance to most other major sights. Ovidio, the man at the reception desk, was extremely helpful- he could always give us recommendations and directions to anything...and the best part was, he spoke great English! We would definitly recommend this place.

We stayed Marta Guest House between 1-3 october 2008.The decoraion was nice-the rooms were clean.İ can say that the best budget hotel we stayed in İtaly.Ovidio(at the reservation desk) was very very helpfull. But our room was noisy.All i can say that dont' pick the rooms that are close to reservaton desk.İ couldn't sleep one night because of the noisy people having conversation at the entrance.
The location was good.Very close to Castello Angello e Navona.İ liked the location.They don't have a breakfast room.They serve one coffe and a kruvasan to your room.That's it.
As a conclusion; as a budget hotel it's clean-the rooms are not very little-staff is helpful-good location.Rooms far away from the reservation desk should be preffered!!