I'm usually a fan of Frommers travel guides. But this one contained only the most basic information and virtually nothing that couldn't be found on the internet. I also agree with other reviewers that the author gives some very biased opinions and promotes certain businesses to the neglect of others. For example, she sings the praises of the Trilogy snorkeling company to such an extreme it makes me wonder if this business wasn't secretly "greasing her palms". Also she says only stay at the Royal Lahaina Hotel if you can get a cottage rather than a tower room. This seems odd, as nearly every Royal Lahaina customer I have communicated with (including family members) says to get a tower room as they have been renovated and now no one wants to stay in the cottages. Based on this it seems that Royal Lahaina would have a vested interest in guiding tourists towards their cottages (as they have so many vacant units) and the author may simply be doing the hotel's "dirty work".
I liked some of the maps. But, overall, I would encourage folks to look for another guidebook. I also have the Lonely Planet travel guide and it is much better. It's packed with useful info and, unlike some LP books, it is not only good for backpackers but people of all travel styles and budgets.