I like Dana's first 500 book, but I'm a bit critical of the second one. She relies a lot on low-carb processed foods in that one, like Carb Countdown milk (not available where I shop anymore), imitation honey (can't find it anywhere), polyols (who needs the intestinal troubles?), and other "frankenfoods" I don't care to use in my lifestyle. It makes low-carbing more expensive and more difficult, since I don't like to run to a bunch of specialty stores to get groceries. And there are a few recipes of hers lately (in the 500 More and the Slow Cooker books) that have been just plain NASTY (the Jill Taylor's Coleslaw and the Peking Slow-cooker Pot Roast come to mind), so I've been avoiding her books lately and relying on recipes I can find online. My DH even went so far as to say "Throw that book AWAY!" when I made a third-in-a-row bad meal from one of her books. There are some really great things in her books, but be forewarned. It really stinks to spend all kinds of money on a beef roast only to have it taste terrible, or to spend an hour or more cooking a meal, then to have everything basically inedible and have to make something else for your hungry family. And who's going to eat those leftovers?
I think the biggest problem is, her testers are way too nice and don't want to hurt anyone's feelings. If something sucks, say so.