Alexio's place really felt like a friend was letting you stay at their flat, it is lived yet tidy with everything you could need to borrow. If you forget shampoo or toothpaste, there's a bunch of toiletries in the bathroom that I'm guessing were left by previous guests. They came in handy, especially some the dry shampoo from the UK :)
The electronic door handle made it very easy to get in and out, you just use a site on your phone to unlock it (we are from Germany and can use data throughout the EU, if you don't have data, it is still possible to connect to the wifi through the door as the router is right there so keep the wifi password on hand).
The building is definitely old, you can clearly hear everything in the stairwell and kids running around upstairs, so it's important to realize you'll be heard as well. Luckily all noise died down after 11pm and the nights were quiet. You should bring earplugs if you are wanting to go to bed early, though. I still prefer this to a hotel because you can get a slice of how the average Roman lives their daily life :)
The one big negative for me is that the bed was very hard. Probably the firmest bed I've experienced in my life other than floor futons in Japan. Also the antique metal bed frame was unstable and shook a lot with any movement. An improvement might be to tighten up or replace the frame, and get a mattress topper for the bed. I'm young and can deal with a bad bed, older folks might not be able to sleep well.
Otherwise, the location was great and we ate amazingly in Trastevere every night. We opted to not use public transit to get anywhere, walking to the Roman Forum or the Pantheon was only about 20-25 minutes. We did use the tram to get to the airport, and the flat is very close to the station which was convenient. For breakfast I highly recommend Caffee Trastevere, the cappuccinos and pistachio cornettis there were amazing and sooooo cheap.