I stayed five nights (extended by one).
Fantastic overall experience.
Anna was friendly, flexible and responsive (especially regarding the extension).
Pros - top 3
* Location - the Colosseum is really close and it's between two metro stops on different lines (Colosseo and Manzoni)
* View - the pictures don't do it justice
* Amenities - great to have a washing machine
Cons
* Hard to find any - I enjoyed staying there. If I had to pick something, I would just note the shower is Roman size, so perhaps not great for bigger people. Otherwise, perhaps a little stereo would be a nice addition.
To comment on some criticisms of another reviewer
* Yes you can hear the guy next door playing Stairway to Heaven sometimes, but it's not intrusive, ongoing or late. Plus, this is Rome, so it's normal to hear something!
* The mattress isn't thick, but it is not uncomfortable. I normally sleep on a very thick mattress and slept like a baby in this bed!
Thanks Anna - I'd happily stay again!