As I plan for a trip next year to Croatia and Slovenia, I've learned that different travel guides appeal to different types of travelers. I'm not upscale enough for Frommer's. I'm not a trust-fund backpacker using Lonely Planet. Rick Steves is for the NPR crowd who'll like his political asides. Nothing wrong with those other guidebooks if you're the audience to whom those books are aimed.
I am finding the Moon Guide to be exactly what I want. It's devoid of politics. (!) It's rather comprehensive, covering the whole country and not just the tourist hotspots. It strikes the right balance for those of us who want to hit some of the highlights, as well as off-the-beaten-track sites. It's full of practical advice on various transportation and lodging options, without revealing any particular political bias in any direction.
One group will find this book indispensable: wine tourists. Winery tours may not be my thing, but this book is full of detailed information on winery tours in various parts of Croatia, mostly Istria and Slavonia (a region completely ignored by Rick Steves, even though it's close to half of Croatia's land mass). If you like winery tours, this book is essential. But even if, like me, you're not into viticulture, there is plenty of other useful information presented agenda-free.
POST TRAVEL UPDATE: This book was very helpful for my tour of Croatia and, to a lesser extent, Slovenia. The Dubrovnik sightseeing and restaurant recommendations were useful. Excellent information on the Kvarner Gulf region. I do have one minor quibble about the Slovenia information. The author is focused on Croatia and her information for that country is invaluable. However, as much info as she provides on the wines of Croatia, she does not give nearly enough information about the delicious variety of wines and aperitifs indigenous to Slovenia! Excellent info for a drinking and eating tour of Croatia. Not nearly enough for a drinking and eating tour of Slovenia!