The Orsa Maggiore has been a fantastic experience. The place is so friendly, all the ladies are very relaxed and open, it must be the atmosphere of the place.
The hostel (actually that is almost an understatement), boutique hostel, would be more fitting, is located just a bit out of the heart of Trastevere, the hip quarter with lots of fantastic bars and restaurant.It is an old villa building with courtyard, one night there even was a jazz band playing in the courtyard. The hostel is women only. It is located in a quiet (as quiet as Rome gets, with scooters) side street and only a ten minute stroll away from the heart of Trastevere. The area feels very safe.
You are within walking distance of the main sights, a long walk though, Collosseum is about 30minutes, same for Spanish steps, etc. the Vatican is about 15minutes walk away, this is also where the nearest metro is. there is no metro or train nearby, I found the nearest train station to be San Pietro or Trastevere, ca 8Euro taxi ride away.
A fantastic start to the day was the Lavazza (!) espresso machines with milk steamer, so you could make your own cappucino in the morning! The rooms are enourmously spacious and have personal lockers (not very secure, but lockable none the less).
The staff has been very helpful in finding the way, explaining how to get to sights and so on.
I thouroughly enjoyed my stay here and will definitely recommend this place to (female) friends.
Oh and, if you would not normally consider a hostel, cause you think only young travellers stay there, the orsa maggiore was a real mix of women of all walks of life and all ages

I stayed 4 nights in this hostel/hotel and I loved it. The staff was incredibly nice and helpful. Gave restaurant recommendations, SOOOO helpful with the transportation information, were friendly and just the best staff. The women who make your bed every day and clean the bathroom are so nice too. The breakfast was not amazing, but certainly fine for a budget traveller. The coffee machines are AWESOME and make the best cup of crema cafe ever. When I was there, women of all ages were there - from 20 to 60+. The younger girls stayed usually in the big shared room with 4-5 beds and less money. I upgraded to a nicer room so my roommates were more my age/shared interests (25-35 years old). I would stay here again anytime!

I love Orsa Maggiore. Of course, I would rather stay in a 5 star hotel! But this hostel is the best accomodation for the price in Rome. Very safe, clean and roomy. Nice courtyard with 2 a bar and a restaurant.

I stayed 3 nights at Orsa Maggiore, and I would highly recommend it to anyone looking to stay close to, but not in the city center - the only reason I gave it 4 of 5 stars for location is that there is not much in the way of Metro stops in Trastevere, so unless you're just going to the Vatican (about 15 minutes up the road) it's a little farther out of the way. The location is in a fairly quiet neighborhood, and although it can be tricky to find at first (v. S. Francesco di Sales is a little twisty), it's actually really easy to get to any main road from the front door. There are quite a few tasty and cheap restaurants just a few blocks down the road (Dar Poeta's pizza is amazing), and the breakfast is ok but the coffee is outstanding. The staff was very helpful with directions and explaining the Roman transportation system, and the entire hostel - including the bathrooms - is spotless.

If you stay there, try to set aside about 45 minutes to walk down to Santa Maria in Trastevere, which is about 10 minutes away - it's a really nice walk and both the church and the piazza are lovely.