Overall, our stay here was great. Very central location to many of the big tourist attractions and shopping. Colosseum and Trevi fountain within walking distance (like 10 minutes or less). Restaurants right outside the apartment around the corner. Lots of additional restaurants within walking distance (again, 10 minutes or less).
We rented the entire apartment which was 3 bed 3 bath. It was on the 4th floor so plan to walk a lot of steps or take the elevator (it's very small and can realistically only hold 1 person and a suitcase or 2 people and no suitcases at a time). 2 bedrooms had bathroom en suites while the 3rd bedroom had the bathroom just right outside the bedroom door. Only 2 of the 3 bedrooms had closet areas and none of the bedrooms had dressers so you may need to get creative if you wish to unpack all your clothes or just plan to partially live out of your suitcase. All 3 bedrooms had their own in-wall AC units with remotes. The bathrooms were all basically identical with rainfall shower heads and a shower wand.
Additional notes and tips:
This apartment does have a washer/dryer though it's a 2 in 1 machine and we could not find a manual for it so we weren't really sure what all the icons meant for the different cycles. It's not a typical washer/dryer brand that you would find in the US so just be aware that you may need to do some internet searches to figure it out. I'd recommend brining your own laundry soap though we did find some pods under the sink that we assume were for the washer (they just weren't labeled or in a box so no idea what brand they were).
Although we rented the entire apartment, based on other reviews, it seems that this company will also rent out individual rooms in the same apartment building so be sure you are selecting the "entire apartment" booking if you do not want to end up sharing common spaces.
To enter the main apartment building, there is a keycode to get in and the door says "Sonder" so it's very easy to find. To get back out of the building, you first need to hit the switch on the wall which unlocks the door. You won't be able to open the door without first pressing the wall switch.
When you enter the main apartment building or you're leaving your apartment, you may find yourself walking into darkness. The lights auto shut off so you'll need to find the light switch on the wall to turn the lights back on.
Not specific to this Airbnb rental but, if you are staying here because you want to see the Colosseum, I highly recommend going online and booking a night tour. It's a unique and fun experience walking through it at night (and it's much cooler without the sun). They light up the Colosseum so the ambiance is very cool. Additionally, because it's after hours, you won't have to fight the crowds as only a few tour groups are allowed in at night (for us it was our tour group and one other). Without all the crowds, it was really easy to take good pictures.