Stayed here with my partner in January after reading reviews on TA. The quality, location are as advertised. Rooms are clean and modern. Location is very convenient: We rarely used public transport, and walked to Vatican, Colosseo, Forums, etc.
One thing that exceeded our expectations was the breakfast service and afternoon snack service: Both were excellent. The room where they serve breakfast/snacks is also a reading room / internet (free) room, and a comfortable place to hang out if you don't want to be in your room.
Desk service pretty good - they all speak English, and are friendly (one of the desk attendants, a male, was the exception -- once he rudely kept me waiting while he finished a personal phone call). Trust them for local restaurant recommendations.
No major problems come to mind. Some have mentioned that there is a lot of graffiti in the area, and this is true, but we never felt unsafe while walking around: It's a populous area.
One thing to be aware of: Getting to the hotel can be confusing if you try to do it on the cheap (as we did). We took the local train, not the Leonardo da Vinci Express, from FCO to Trastevere station (not Termini) and then caught the Largo Argentina tram from there. Take this to the last stop before the Tiber - the stop is called Belli - cross the street and head away from the river for 1.5 blocks. turn right on via della lungaretta (a small busy street that's not well marked) and walk until Piazza Santa Maria (this is a prominent Piazza and available on most every city map of Rome). you'll know when you're there. go right on your first street after blue ice gelato, and then veer back to the left on vicolo del piede. hotel gate is on the right.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.