Monica's place was lovely, very cosy and clean. It's well located and there are other things to see besides the Colosseum - the church Santa Maria Maggiore is very close by, and it's fantastic!
The picturesque Monti area is also near - and makes for a wonderful stroll around beautiful streets leading up to the Forum, Trajan's column, etc. The apartment itself was beautiful, communication was prompt, so I'd definitely book it again if I were to revisit Rome.