We chose this accommodation (St. Peter Vatican House) because we have read so many good reviews, however, we have found that this accommodation is far from good, it is just ok.
The accommodation is located on the first floor of a multi-stories building block, when you entered the front door of this building, it has stairs (no lift) leading to this accommodation.
The accommodation is actually a flat/apartment, owned by two owners. The owners do not live in this flat or in this building. When you enter the flat, it is a narrow hallway separating two double rooms on your right, and the kitchen and two toilet/shower rooms on the right. There are no air-conditioners in the hallway and kitchen. In summer, it is very hot. The kitchen is very small with basic facilities including an electric cooker, an oven without any baking trays, and a fridge-freezer, there is no microwave oven, no dishwasher, no coffee machine, etc. in the kitchen. The cooking utensils are also very basic and limited. The main electric board keeps tripping, and thus you cannot use all the electrical appliances at the same time, while the kitchen sink keeps blocking, and eventually, they had to send a plumber. There is a fan in the kitchen so it is not too uncomfortable to eat in the kitchen.
In the two bedrooms, each room has a single bed and a double bed, and an air-conditioner. One room has a desk, the other room has no desk but a two-seater sofa. The air-conditioners are EXTREMELY noisy and one remote control is not working as it only has one battery instead of two. Therefore, prepare your ear plug if you want to get a good sleep. The capacity of the air-conditioners is small, with hot weather like the day we arrived, which was 37C, by even setting to the lowest temperature, the rooms were quite hot all day and night long.
The condition of this accommodation is far below the photos shown on the AIRBNB website. The photos are really misleading. The headboards of both double beds were worn out, the wall paints around the window in the shower room were failing off and were very dirty, the entry door is like those in a slum area ....
The owner (Livia) does not speak any English, and she is looking for money all the time. She offers to arrange for somebody to pick us up at the airport at the cost of 60 Euros, but a taxi from the airport to the accommodation cost us 31 Euros. We asked her if we need to book museum tickets before we travel, and she directed us to her friends who provide expensive guided tours. We have informed her about our flight arriving at the airport at 9:30 pm beforehand, however one day before our departure, she requested us to pay 30 EUROS late check fees….
However, the caretaker who met with us for check in was extremely nice and helpful, she explained everything to us including where to shop for groceries, where to eat, where to visit, ...

On the other hand, the location is very convenient as other reviews have indicated, and no need to repeat it here.
SOME PRACTICAL TIPS:
No. 1. Taxi in Rome does not have a good reputation, however, we have found no problem at all in using the Taxi. When you leave the airports, go directly to the Taxi rank, and just queue for a Taxi, do not talk to anybody who offers you a Taxi. The tariffs on taxis in Rome are based on zones with fixed fares just like the metro, for example, from FIUMICINO to the city centre is €50, and from CIAMPINO to the city centre is €31, .... Official taxi is in white colour with a TAXI sign on the roof. The front door displays the license no and the tariffs. In the city, if you want to call a taxi, we can download the FREE NOW app from App Store, and order using the app, the app will ask you to pay a fixed fare depending on the zone you are going to, and the taxi should arrive with a few minutes. This should be the most reliable and trustable way to call a taxi.
No. 2. For visiting Vantican museums, although visitors are required to book tickets online, we actually saw people purchase tickets on spot at the museums where we change our booked tickets.
No. 3. There are many English websites selling different tickets, such as train, museum, ..., many of them have an ending of ".com", rather than ".it" and therefore they are actually not the official websites. It is not easy to find official websites. We used google translate to translate English to Italian and then used the translated Italian words to search, and then we found the official websites, and these official websites normally also have English versions. It should be safer to use these official websites to purchase tickets.