My stay was amazing. The service was above excellent. The lobby and entrance is fantastic. Highly recomend it to anyone wanting to stay in Rome. The location is great as well.

This is one of the best hotels we've ever stayed at. I base this on proximity to transportation and sites, lobby area, check in clerk, concierge helpfulness, room cleanliness/size and bed comfort. The hotel was close enough to the bus or subway line, but we took a taxi from the Rome train station for 10 euros. You get white glove service from the moment you arrive. The hotel clerk shows you to your room and explains the basics to you so that you can get comfortably settled into your room. We are Starwood members, but not that frequent so I was surprised when we were upgraded to a gorgeous room. Maybe, this is standard for a deluxe room, but we had a sitting area with 2 chairs table and couch, a desk/tv area and then a large bed area that had a feather bed top (but still 2 twins pushed together). The bathroom was a very long, large bathroom with a great soaking tub, vanity area and double sinks area separately. The shower could have fit 20 people inside. But the most impressive part were the Hermes toiletries. My husband loved them so much we purchased more in London. There was turn down service and they also put some lovely music on the nice stereo system in the room so you could relax after a long day. The internet was extra at 15 euros/night, but everywhere in Europe is extra it seems. We ordered room service after a really long day on the train and it was very expensive, but expected for room service at a hotel of this caliber. We paid 60 euros for 2 diet cokes, a club sandwich and a ham and cheese sandwich. The diet cokes were 8 euros alone. The portions were large though and we could have easily shared 1 club sandwich. The other must mention is the complimentary candies they restock daily in the room. The are called Perugina gelees candies and once you try them you will be hooked. Make sure you buy some when you are in Rome as I found out when back in the U.S. that they cannot be purchased over the internet. It's worth the trip back to Rome just for those candies.

just returned from a 6 nite stay at the St Regis.
ROOM:
-stayed in one of the Imperial rooms on the 3rd floor overlooking the Piazza d. Repubblica. the room was huge. service impeccable. the bed is incredibly comfortable. very quiet. could not hear any noise from the hall or from either side of us or above us (i believe the 4th floor is the highest). apparently the hotel was fully booked while we were there so the rooms were occupied. I do agree that it is hard to tell where the 40million dollar renovation was done. my guess would be the all marble bathrooms, which were great. spotless. the hermes products are a little overpoweringly scented in my opinion but if you like that, it's great. there was a tub and marble standup shower--terrific water pressure.
HOTEL SERVICE:
-did not dine at the hotel; ordered room service once for a VERY early bkft--arrived right on time at 6am as requested. and it was delicious.
-the average age of the guests is probably above 40s. we are in our 30s and were definitely among the younger guests. did not see any young children so it was quiet. the main area off the lobby is beautiful; can enjoy the piano music at tea time or while sipping an aperitif. very elegant.
-Mario Santulli, head concierge, was great. I am a compulsive planner. emailed him an entire list of reservations for restaurants and events that needed to be done for our trip and he took care of all the details flawlessly.
LOCATION
-it is within 15 minute walking distance to the colosseum area, 20 minutes to the Piazza Navona. Definitely worth taking the time the first one or two trips out, but to save time (and our energy...it's hot in September--sunny mid 80s) we took cabs everywhere (we're from new york city--we're used to it, as we are used to the traffic noises that may bother you if you are from a quiet area--there are sirens, traffic sounds; for us, it was just like home and slept right through it all).
-yes, it is very expensive. but if you can splurge a little, it's worth it.
-we had NO regrets about our choice

We started our trip to Italy by staying our first three nights in Rome at the St. Regis Grand Hotel Rome. The hotel is very nice, and the staff does a nice job as well. We arrived around 9pm as our flight was late. Our room was very nice and large, especially for Europe and had a view of the interior courtyard of the Hotel. We had requested a rollaway bed through the web site, however at check-in there was some confusion and they told us it would be an additional 99 euros. Of course we had to have it since our son was traveling with us.

We ran into problems with the shower, as it would not drain, and the glass door to the shower would not close. We reported it to Engineering but they only fixed the drain, not the door. So we were dissapointed, especially with this being the St. Regis, the best hotel in Rome.

The hotel itself underwent a $40 million renovation about 10 years ago, and is starting to show its age again. The location is nice, but a little out of the way (the Westin Excelsior and Hotel Eden are closer the sites and restaurant row on Via Veneto).

The Concierge was very nice, and did an excellent job.