We bought this before a recent weekend away in Rome (ok, I confess, we went to watch the rugby!) As we thought it would be nice to know a little about what we were looking at and where we were.
I spent the delay at the airport and the flight checking through the books for hints, tips and ideas and was very proud of myself when we confidently strode through the airport to get on the train, which I already knew would drop us at the central station where we would get the bus which would drop us just by our hotel.
The train cost 12Euros rather than the 11 the book said, but we found out on the way home it is 11 at the normal cashiers and 12 at the "express" service. So I let the book off for that.
I didn't forgive the book for neglecting to mention that the busses don't stop at all the stops mentioned unless you ring the bell - which you can only do if you know where you are! So we ended up hopelessly lost and wandering the streets of Rome with luggage! Which would have been fine but the maps in the Rough Guide are, most definately, rough! If you have to rely on them alone for any length of time, take a compass! It is impossible to know which direction on a road you are going for hundreds of metres because the little roads aren't named - very frustrating! Eventually we found our hotel (not mentioned in the guide so can't tell you if their hotel reviews are accurate I'm afraid), and collapsed exhausted after our long walk!
The next morning we set off to see the sights armed with the book and a better map courtesy of our hotel! The descriptions of the colloseum, vatican, panthenon, roman forum and various museums provided a good starting point for a tour. They give enough information for you to know what you are likely to be interested in and to give you a basic overview when you are there. If there is anything you are particularly interested in you may find the guidebook a little light and a guided tour/ more detailed book may prove more use.
Having said that the diagram of the set out of the sisitine chapel told you all you really needed to know while you were actually looking at the artwork.
That evening we picked a restauraunt from the book near to our hotel. Unfortunately we chose badly as it was actually closed for refurbishment! We ended up in one down the road whish was pretty good though so no major problem.
Another day of tour book guided sight seeing followed, I personally liked the little bits of more local knowledge in the book, such as the short write up about the cat sanctuary in LArgo di Torre Argentina, as I felt they added a bit more to the whole experience, not so related to the major sites.
On our third night we visited Ai Marni restauraunt, a Rough Guide recommended restauraunt in the Trastevere. It is a great place to go and experience something a little more Roman than the usual tourist haunts and I would highly recommend it. We would certainly never have gone in as it looked like a fast food bar from outside, without the help of the book.
The guidebook also includes helpful information such as language guides and guides to bars, shops and kids entertainment. It was certainly helpful with things like guide prices for taxis (some hotels offer a shuttle which is much more than a taxi would be) and finding little restauraunts and cafes. In terms of details about the major sites it was a little light for my tastes. However, I think it would be difficult to include more info on all monuments without makin the book too big to take away with you!