I'm not really sure how to answer this. For me, the lites are a LAWL approved "treat" and they are very satisfying--to me. There are certainly others if you are just looking for a snack. There isn't anything "special" in the Lites just part of the program for some of us. Other comparable bars are Luna's and Kashi Go Lean Crunchy. Hope this helps.
As long as you count 3 points for the lite bar, I'm sure you can have it on WW. I don't think the Lites speed weight loss; there's no magic ingredient in them that I am aware of. If I were doing WW, I'd probably look for a 1 or 2 point treat (something tasty, but high in fiber and protein).