My husband and I were in Rome for only 3 days (which is way too short!), pre-cruise. It was important for us to stay in a place that was convenient to reach from Fiumicino airport and also that we will be able to reach Civitavecchia port for our cruise with ease (and cheaply). In this aspect, Guendalina’s place in Trastevere was great for us, as it is literally 5 minutes away from the train station from which there is a direct train to/from the airport and the cruise ship port.
We also enjoyed how peaceful and quiet the place is. We had windows closed for the night (with A/C on), so it couldn't hear any noise from the street.
The apartment is very clean and has everything you need for a comfortable stay (well, except for wine glasses :)). The bed/mattress in the main bedroom is also very comfortable. The terrace is lovely and makes the apartment feel large and airy. Good supermarkets nearby.
Overall, we were quite happy with our stay in Guendalina’s place, just wish it had been a bit closer to the center of Rome (in a "perfect world"!). It IS easy to reach the center by tram or bus, however considering heavy Rome traffic, it takes awhile (around 25 minutes to Piazza Venezia). Underground station nearby would certainly have been a great thing, but it's not a reality.
We had a great time in beautiful Roma and recommend Guendalina’s apartment for people who are happy with being in a quieter part of Rome and a little away from the center.