I guess it's really up to you. I used the old WW points formula years ago and lost weight. I don't know exactly what the "new" forumula is.
FitDay is so easy to use and sure works well, so I'm a bit biased in that respect. For long term weight loss and maintaining, I do think it makes sense to take control of your calorie/nutrition mix.
47 M 5'8"
May 4, 2010...... 440? lbs. (Start FitDay Size 60 Jeans)
June 19, 2010.... 393 lbs. (First Weigh-in)
June 19, 2011.... 229 lbs. (164 lbs. gone in one year :-)
Current Weight... 185 lbs. (Size 36 Jeans)
Next Goal 169 lbs. (07/04/12)
Ultimate Goal 165 lbs. (12/31/12)
The best exercises for weight loss are Fork Putdowns and Table Pushaways.