If you are looking for a small book to fit in your back pocket, The Rough Guide France is not for you. If you are looking for a guide that lovingly describes even the smallest French town in careful detail and clear format, then this IS the guide book you should be looking for.
The Rough Guide to France does an excellent job in several areas where many guide books fail. For example, smaller attractions are often overlooked in favor of the larger cities, such as Paris or Lyon. Rough Guide ensures that for those who want to go provincial, they won't be going in blind.
Another merit of the guide is in it's clear, concise format. Not overburdened with irrelevant maps/illustrations (a pet peeve of mine), Rough Guide has clean, simple directions and mapping. This is a vast improvements over Guides like Lonely Planet, where I often feel the editors publish more with an eye towards their own self-satisfaction than towards the serious traveler.
The resturaunt/hotel features are adequate, frequently include useful maps, and will not tax anyone's checkbook too harshly.
Perhaps the greatest strength of this guide is the seeming conviction of the editors to tell you that which you NEED to know for that trip to France. Michelin might the cultural ask-all, DK may have lots of lovely photographs, but Rough Guide is for when you're ready to get serious about your trip to France.
Well-written, informative, with a clear and honest style that should impress both casual and budget traveler alike, The Rough Guide France should be your FIRST PICK in guide books.