Even by European standards this hotel is not a 5 star. Yes, if you want a big room on the most expensive street in Rome, then book here. The rooms and bedding are outdated and old. The beds were uncomfortable, no covers, and the bathroom was small (not unexpected in EU).

If you want location and "comfort", then go to the InterContinetal at the top of the Spanish Steps. The rooms are smaller, but the bedding is cozy comfort and the bathrooms are much bigger (Rm 123 is great!), or ask for a room with a view of the inner courtyard.

The only saving grace at the Marriott is the breakfast buffet, that was included because of my status. And Sonya the front desk lady that works the evening shift.

My wife and I stayed here on points recently. We found the service was excellent at the hotel with eveyone from the door man to the concierge very proffesional and friendly. English seemed to be the dominant language at the hotel.

We were in one of the smaller rooms in the hotel and it was small though since we were not in it much this wasn't a problem. It certainly would not have been good if we had are kids or if we were needing to spend more time in the room. By contrast, the bathroom was a very good size. Both were classy, comfortable, and clean.

As nice as everything was, had I been paying for the trip I likely would have stayed somewhere else. While in a very nice part of town I could have found something a bit closer to more of the tourist sites since we like to walk everywhere and this Hotel was kinda on the edge of the tourist zone. Also, for the price I think several of the other hotels in the area seem to be even more elegant but I can't vouch for that for sure.

I did think the room service breakfast was a bit over the top expensive. We didn't eat at the restaurants (though we had planned to) but they seemed more reasonable based on the location and the menu's looks pretty good.

This deluxe Marriott at the end of the Via Veneto is a classy experience by anyone's standards. Contrary to some comments posted elesehwere the hotel is trivial to access by public transport with an underground/metro entrance across the street (though it connects to a tunnel that is around a quarter mile walk to the spanish steps metro station). I would recommend the first time user starting from the hotel rather than the station, learning the tunnel, and then it is easy after that, a bit of a maze and you need to find the right borghese escalator to get to the front door of the hotel).
So, with the cheap and reliable metro access to all of the sites you will want to visit (Varican, colliseum, so on for only 1 Euro per ride) the other pluses are that this is a relatively calm and classy area of Rome, no one hustling you, plentiful expensive and also value restaurants to choose from, a safe, ATM filled neightborhood with the old Roman wall outside the door.
The concierge and front deck folks were courteous and of Marriott standards, which may sound obvious but in Rome sometimes that is appreciated!
This is an expensive hotel and one of the premier Marriott properties, but I would go back in an instant, I am a Marriott frequent guest but I do see the faults at some of their properites, there were none to be found here (with perhaps the exception that the gym is somewhat lame, if you feel the need to have the full equipped workout room this hotel disappoints in that area versus many other Marriotts).

This Marriott was really great - it felt more like an Italian brand rather than American; not that I am anti-American hotels, it's just that we like to get the local flavor. The only downside was the restaurants on this street were either way over-priced or too touristy.