The Residenza Vaticana is very different from anywhere else we have ever stayed, so our initial reaction was, it was very small. The room we were in was compact but quiet. The shower was a godsend as the temperature in Rome was Brrrrrrr cold, therefore a lovely hot shower soon warmed us up, not together as it wasn't big enough. As the breakfast (continental only) was served in your room, there was no chance to interact with any other guests and therefore we felt a bit isolated.
We found the surrounding area in the evening very very quiet and not many places to eat if you don't like Italian food. There is a good Pizzeria up the road though which was lovely for a snack during the day if you were around that area. If you do want a lively night life you can travel by Metro into Spagna etc. which is where it all seems to be buzzing at night.
However, if you are just in Rome for the sightseeing, then this is a good base and we could not complain about the staff and management as they were all very helpful.
A tip from the wise...get the airport bus to Termini and then grab a taxi to Residenza Vaticana. We went from Termini on the metro to Lapanto and then it took us about an hour to find the B&B by which time we were biting each others heads off. We only did this because we were advised not to take taxis as they charge the earth but negotiate the price before you get in the taxi.
To end on a high note, Rome was fantastic and well worth the visit. Enjoy.