Frommer's Los Angeles Day by Day was written by Garth Mueller, and -- at the time it was published, last year -- came out from a venerable publishing house with which I am also associated. (Said venerable publishing house has since sold off that piece of its operations to the not nearly as venerable but vastly cash-rich data octopus Google.) It's pocket-sized -- slim but taller than a mass-market book, with a large fold-out map in a pocket inside the back cover and several other maps of specific areas in a three-panel fold-out from the front cover.
It's organized by interest rather than geographically, with chapters on shopping, dining, lodging, nightlife, outdoor activities, and arts & entertainment. But it opens with the author's curated "best of" recommendations -- first, suggested itineraries for one-, two-, or three-day trips, and then a half-dozen specialized day trips for particular interests (fans of movies, architecture, rock music, art, shopping, eating, or those traveling with kids). Assuming that Mueller's expertise is what it should be -- which I can't evaluate at this point since I haven't made the trip yet (and I don't expect to follow any of these suggested tours explicitly, anyway) -- this is the most useful part of Day by Day, giving travelers a template to start from when they plan their days in LA.
It has a crisp, authoritative look, with "tabs" for each section embedded in a color bar to make thumbing through easier, and there's a lot of color photos, though many of them are presented postage-stamp-size. The two-column layout presents a lot of data in a way that keeps it all easy to follow, and occasional sidebars give more detail on specific points.
The bulk of the book is written in capsule-review style, like listings in Time Out
Lonely Planet is also clearly hipper than Frommer's is, from the open-shirted author photo of Adam Skolnick to its focus on neighborhoods (the trendier the better). It does have a quick "do this each day" section up front, possibly to compete with Frommer's, but the book is primarily organized geographically rather than by interest, starting with Hollywood and circling around to hit Beverly Hills, Downtown, Santa Monica, Burbank, and excursions to points further away.
Lonely Planet feels like it gives more space to shopping and nightlife -- again, aiming at a hipper crowd than Frommer's -- so visitors with those items high on their agenda will want to gravitate in this direction. It also is quite thorough in differentiating between the different strands of nightlife: old Hollywood, new Hollywood, LGBT, and so on -- to give the reader the best guidance as to exactly which trendy club she will be most comfortable in. But all that hip trendiness can make an older, stodgier, less shopping-obsessed reader -- your humble correspondent, for one example -- feel bored and out of place; this is not a guide for those who don't intend to make hitting boutiques and/or nightclubs a major part of their LA itinerary.
The design is bright and modern, with pastel headers and sidebars to organize sections, and lots of color photography -- as expected from Lonely Planet, it's entirely up-to-date in both tone and style. For readers who are equally up-to-date, this is the perfect guide to LA. (The rest of us may want something a bit more sedate.)