I've read Primal Blueprint, The Paleo Diet, Robb Wolf's book, and a few others. I've started out not completely cutting out carbs (used to love bread/pasta/pizza/rice/etc...) but cut out all the simple carbs and sugar (beyond fruit). Slowly, I've cut out pretty much all non vegitable/fruit/some dairy (yogurt, cheese, kefir) carbs. Over last 3.5 months between eating right (no calorie counting mind you, with lots of variations available) and hitting the gym hard (weight lifting more then cardio even) I went from 298 lbs to 248 lbs (lost almost 9% body fat) and gotten a lot stronger so I was gaining muscle (I am 6' tall).
So in short, Primal/Paleo diet works (I like Mark Sisson's book and approach as well as marksdailyapple.com site best), but what is even better is doing weight lifting (yes, even for women) and some cardio in addition to that. Still early for me on the program, but overall I can see this lifestyle change working mainly because I don't count calories and I am not really hungry.
What's somewhat amusing is that I used to drink a lot of coffee (talking probably 5-6 cups daily) and now I drink almost none (will have a cup couple times a week) and I have more energy then ever and feel better then I have in a long time. Carbs are truly evil!