Here's my experience of a couple weeks ago as a diamond member:
1) nice large western-style room with nice large marble bathroom.
2) Executive floor with nice executive lounge, with breakfast each morning, and complimentary snacks and drinks in the evening
3) Bus service 6X a day, starting at 10am, running every two hours approximately, with the first bus back to the hotel from Downtown at about 11:30am, last bus back is at about 10:30pm I think. It drops off and picks up right by Capitol Hill/Vittorio Emmanuel Monument (sp?)
4) Because we wanted to get an earlier start than getting into town at 10:30am on the bus, we paid for the train each morning. The first express train to Termini station leaves at 7:37am. It costs about US$8 per person per direction. However, there is another train (leaves from track one, not track 3, which is the express to termini) which is HALF the cost, but does NOT go to termini...but it DOES take you, in the same amount of time (actually a couple minutes less) to two different train stations which both have Metro stops...so if you want to just get to the metro, you can do that in less time with less money by taking the other train.
5) didn't use any other hotel facilities, except room service/restaurant. Prices were predictably over-priced. $15 hamburgers, etc.
6) VERY nice to simply walk out of your flight from the US with your bags straight to the hotel via the walkway, into our room, quickly freshen up, and be on the way to downtown rome...then at the end, simply pack your bag and walk to your flight. No struggling with luggage all the way into town.
Those are my thoughts for now. If you don't mind 30 minutes to and from downtown at the beginning and end of each day (it was no big deal. The bus was very nice, and the train was, too!) this is a great option. Check for point stretchers. That's what we used!