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.

This was a beautiful hotel with an ideal location for walking and travel by car out of town. The rooms were nice and very clean. Our view wasn't so great but overall it was a beautifu hotel. I felt the staff were a bit rude at times and I felt they didn't want to be bothered by an American. When I asked to send a letter and how much it would cost, the gal at the counter shook the the letter and said she wasn't sure. There were times when the front desk staff wouldn't even look up at me for assistance. Nice hotel, the Marriott name does carry weight but I had no use for the front desk help and there was a bell boy or someone who kept talking on his cell phone while he was working and was a bit upset that I had luggage in the lobby sitting while I was waiting for my spouse to come pick me up and the luggage up by car. The location was ideal and the are beautiful. Very expensive.

My husband and I stayed at the Grand Flora on our honeymoon. Though, we are American and maybe it was to be expected...the staff was incredible rude to us. Any question about restaurants, shopping, etc. was a complete bother to the front desk. I am a Marriott Gold Member and was refused a room upgrade...we had a lovely view of the side of a building and garbage dumpsters.