I've done WW here and in the US, and both times, lost weight -went to the meetings, which I think helps. However (and this is just my experience), I think the program pushes a lot of it's own food, and that stuff is highly processed and of little nutritional value, just low in points. The ready meals, desserts, etc - all loaded with sodium, preservatives, etc.
Now, I kind of use my WW books as a guide when I go food shopping, but I don't hardcore count points, I count calories at sparkpeople so I can also track protein, fat, and carbs. The weight comes off slower, but I feel healthier. My point allowance on WW didn't allow me much food, usually, so I didn't have the energy to workout as much as I do now.
There's good and bad. It definitely gets you going in the right direction, but I think figuring out a healthy lifestyle that doesn't rely on x points per day or whatever is the best bet.