Originally Posted by Perche

1. G Rough is in an excellent location. The St. Regis is in a terrible location, a 20-30 minute walk to anywhere you might want to go. You'll always be using cabs. Like Boscolo Exedra, it's in a terrible location near Piazza della Republica and the train station. These are the least desirable places to be. The only place that rivals St. Regis and Boscolo for terrible location is staying at Piazza Barberini, but at least Barberini has the saving grace of not being near the train station.

St. Regis and Boscolo are great hotels, if staying in a hotel outside of the main area and having a big American breakfast is what you are going to Rome for, but not so good if you are going to Rome to see the historic, beautiful, and romanticRome. G-Rough is much better situated, and more economical. Unlike Boscolo, St. Regis, Barberini, when you go downstairs you won't need a cab to go anywhere because you'll already be there, in the heart of the historic center.

2. Palazzo Navona and G-Rough are right next to one another, so it's dealers choice. Both are optimally situated.

3. ?Hotel Artemide. It's further from the train station than the St. Regis or Boscolo, which is good. Still, it's not at the heart of things. Via Nazionale is a very commercial street, with cheap clothing stores, lots of buses, noise, traffic, etc. You are not going to want to wander outside and sit outdoors at a coffee shop, because you'd be on a major, noisy street, with horns honking, buses going by, etc, not on a historic, cobble stoned plaza. That area of Rome, Boscolo, St. Regis, Artemide, is not the part of Rome that people have in mind when they think of a postcard from Rome.

4. Manfredi is not too far north. You'd be less than five minute walk to the Spanish Steps. Via Babuino is a very upscale street. Not exactly a romantic street, but still one of the better ones. This is an excellent location.

The only ones that are not well located that you mention are St. Regis and Artemide. Take TripAdvisor with a huge grain of salt. The others are all well located. The only time you want to be near the train station is if you are arriving to downtown Rome at 10 at night and have to catch a 7AM train out.

The only time you want to stay near Piazza della Republica (St. Regis, Boscolo Exedra) is if you are going to Rome for a business meeting and don't care about the ambience of the city, if you plan to not leave your hotel, or want to be in and out of cabs to get anywhere interesting.