We've enjoyed staying in this place. It's about 15 minutes walking from Termini station (or about 7 minutes bus ride). We found the flat to be close enough to all the checkpoints in central Rome to not bother with public transport on some days (but if you want to take a bus to the center the bus stop is around 2 minutes walk).
Since we were working quite a bit while there the large kitchen with a table was very useful and since the kitchen was fully equipped so we could even cook at home. A small grocery store is around 30 meters from the apartment.
When we are back in Rome we are quite likely to come back to this apartment.