First time in Rome, hence this is strictly personal opinion. :) Location - 200-300m from Vatican entrance. What was seen in the acommodation decription, same was found. (everything superb and comfortable, met our expectations). It is a room with personal bathroom in a 3 room apartment. Neighbours can be heard - wasn't a problem for us. Bathroom - if you are >2m high and >120kg - could be chalenging :).
But the main thing - SUPERB host. From the check-in (which was actually late one) till the farewell - top notch!
If you are in Rome, you are easy going person (not a pathological complainer about everything what is different from you mama's house) and you need a central place to stay, easy accessible, to sleep over between exploration days - that's the point. If you want to live in the center and can't afford a penthouse i Rome Marriott - that's a reasonable choice.