Hi,
I haven't used slim and save and although at first look it appear much cheaper it isn't. To do the equivalent of SS for example you would have 4 Save & Slim products at a cost of £38.99 (they also suggest having selected salad or veg on top of that so more cost). Plus for me the biggest benefit of CWP is my consultant who I visit or can call, text or email, and have a real one to one relationship, not faceless web support. So for a saving of about £1 a week I think I would stick with CWP