I was on WW and I gain everything back and more.. Reason? They dont teach you why its bad to eat certain food, its just: dont do it.
Counting points is also a hassle and finally, it doesnt make any sense to be allowed to eat w.e you want, just count calories(in points obvisouly)... some calories are good for you some are not.. shouldnt put them all in the same basket..
Same idea for fats for example... not all bad for you or grains!
SO
my point is: this diet is the only one I was able to keep and I will for the rest of my life because it is not a diet as in dieting, its a way to eat.. a way to live
I suggest reading the sonoma diet book. Lots of explainations and why it is such an awesome way to lose weight.
Like Sarah said, you loose about 1-2 pounds a week except the first 10 days.
But also, it is SO much more.. when I lost weight with WW, I find my body was odd looking...it was almost like it wasnt natural. With this diet, my skin got better (color too weird huh), my energy levels are higher, my body shape is awesome and I dont know how to explain it but I just look healthy even if I have many pounds to go!
Try it