I love ww classes. I really don't like sw classes, and got nothing from them. But I love my ww class and look forward to it every week.
As others have said, portion control is the biggest thing. I need to be restricted with my portion sizes, but don't want to be restricted in what I actually eat - so ww is perfect.
I got a bit fedup after getting to goal of still being obsessed with points, so I turned to sw. I find it great for maintaining, but as soon as I need to lose a pound or two, I go straight back on ww to actually lose - I can't seem to lose on sw! I have just accepted that tracking and pointing is part of my life forever, and am back to enjoying doing it.
The nature of the discover plan is to encourage you to mainly eat foods that are really filling. This really helped me because on the older plan, I tended to cut back on points by cutting back on protein - for example if I was having pasta, instead of reducing the amount of pasta - I would leave off the chicken instead. I now understand the chicken is more filling than the pasta, and therefore I take a little less pasta and a bit of chicken, then bulk out with veg. Therefore its helping me to have a more balanced diet.
However my spell doing sw really helped me eat a more balanced diet as I got a taste for foods that I previously didn't eat. For example I never used to eat fruit (tho I ate loads of veg) or yoghurt because I thought they were a waste of points - now I eat them everyday. I really wasn't having any calcium at all - thats my fault, they do encourage you to include calcium rich foods. However I love how sw build it into the plan so that you must have calcium everyday, and fruit is 'free' - I wish there was a way ww could do this - but I appreciate it doesn't really fit with the plan. And I realise that really we are responsible to ensure our diets are balanced.
I am waffling now lol! Good luck anyway, whatever 'diet' you pick.