I personally find that calorie counting is a great way to lose weight, but sometimes it's not as good because it doesn't allow you the flexibility to have something without limits in case you're still hungry. I like the flexibility of Weight Watchers: I have lost 84 lbs with it and kept it off for nearly a year now. I eat loads (literally!) I don't give up going out or social gatherings, but I still maintain my weight really well. Even not at Christmas time I have gone over my goal of 8st 9lbs.
The new propoints plan weights calories differently depending on how much hard work does your body to break down the nutrients in the food you eat, so it encourages you to eat more healthily, e.g. more fruit and vegetables, which are almost always 0 points, and less points for the same calories when the food contains more proteins and less carbs, as your body works harder to break down proteins so the calories you actually ABSORB of the protein-rich food are less than those of the carb-rich food.
Also, remembering single figure numbers or early teens numbers is easier for your mind than hundreds or thousands, so remembering for example that a food has a 6 points value is easier than thinking that it has 283 calories.