We really enjoyed our stay at Marco's place. It's charming, pleasant and well equipped, and though it's small, we felt that as a couple we had everything we needed. The shower is quite tiny (especially for big guys), but we managed :)
The location is perfect - super central in lovely Trastevere, with a huge variety of restaurants and bars within a minute walk and beautiful alleys to wander around, yet the soundproof windows do a great job so the apartment is very quiet.
Moreover, Marco is a great host. He welcomed us on our arrival and was very friendly and informative, giving us lots of local tips. He was also very helpful with some questions we had during our stay.
Very much recommended!