Great location, very close to the colosseum and approx. 20 minutes to the centre with most of the attractions. The apartment has everything you need. It is functional and value for money but not for people who expect luxury (which we did not need because we were exploring the city most of the time). The shower is quite small but acceptable. No problems with the self-check in.
Simone is very helpful and always open for questions. I can only recommend staying at his place!