Great location near enough to Termini for convenience but far enough that it was very quiet. 11pm curfew, but that didn't bother us as we were stuffed from all the walking during the day. Sisters were great hosts. Rooms were very clean and spacious with own bathroom. Breakfast of rolls, jam, coffee/tea was nice. Common use terrace on roof was great for a simple takeaway meal at night. Close to supermarket, cafes, bars and takeaway. Found on eurocheapo.com but booked directly via [--] Definitely would stay again.

Having read about the nasty smell in number 14 I dreaded to enter our room after being shown to - guess what - number 14. I fact, there was a mouldy smell in the beginning, but after tracing the stench back to its origin in the shower drain it could easily be prevented by putting a folded plastic bag over it and weighing it down with a heavier item.
Furthermore, number 14 is equipped with ancient paintings and a beautiful coffered ceiling. The beds are comfortable and the room provides an enourmous lot of space.
As I heard and eventually saw, the equipment of the other rooms is more modern.
We spent a fabulous week in the convent. Every single one of the nuns was outstandingly friendly, the breakfast coffee is excellent and the location perfect. Termini, Rome's major railway, metro and bus station, is a 10 minute walk away. Just across the street a cosy Irish Pub can be found and an excellent ice cream parlour (L'Orso Bianco) is just around the corner. And the view from the terrace is overwhelming, the Colosseum and St. Peter's could easily be spotted.
The only downside is the curfew at 11pm.
The early breakfast time (7am onwards, Sun 8pm onwards) on the other hand were quite handy, as we set out early and thus could make the most of the day.
I would definitely recommend this hotel with its lovely athmosphere, setup and people.

PROS:
Central location, 10 minute walk to termini, SMA grocery across Santa Maria Maggiore, nuns are very nice, especially Sister Andrea who prepared breakfast for us at 5:30 AM (we had to leave at 6:00 AM for an early flight).

CONS:
Room #14, where we stayed, smells bad (from the bathroom), shower is very slippery (I slipped & skinned my elbow, very thankful I did not break any part of my body), door is a challenge to lock & unlock, room facing the breakfast area.
BOTTOM LINE:

I would stay there again,BUT I would be VERY SPECIFIC I DO NOT WANT ROOM #14.

We stayed in this charming convent that was located close to the main train station. It was a most excellent location and area. We awoke each morning with the delightful sound of the nuns sweetly singing on their way to the chapel. The rooms were large..very clean but minimal. We would stay there again.