Elena’s place is wonderful. It’s a little snug, but the patio is absolutely worth it. Stay a few days to make sure you can use it and relax with the views! The sofa bed is indeed very comfortable (we were a little worried with injuries) but just as good as a normal bed!
The kitchen is well stocked, and the bathroom is spacious.
Even though the unit is almost all windows, it was not overly hot and the AC worked well.
Elena and Simone were very quick and friendly when responding to inquiries of ours in the days/weeks before our trip and even afterwards! She is a fountain of knowledge and Simone was gracious enough to help carry our very heavy luggage up the last bit of stairs (the elevator goes up about 3/4 of the way).
The Vatican was not noisy with bells, so you can sleep in or nap as you need (outside of 630). The train is close and lots of shops and restaurants around the unit. Very easy to walk around to all the monuments.
If it’s available - absolutely book this place!