There's a lot of flaws in SW, there's a lot of flaws in any diet. But if you stick to the basic premise of eating until you feel satisfied (rather than full) even if you're technically ALLOWED 389464639 bowls of rice a day, you won't want them, because of course, you'd have to have 1/3 of salad and veg to go with them.
You can save up syns (I did and still lost) I could have a McFatTwat's on a Saturday morning without a gain on the Monday. IF to was rigid with the basics all week.
It's not going to work if you think too hard about it, but then, neither is anything.
1/3 salad/veg, 1/3 carbs, 1/3 lean protein... if you stick to that in the early weeks, you will lose and you won't 'miss out'.
I used all my syns for wine.. not healthy, but I could have just as easily used them for an avocado.
It's quite a free plan... you tailor it to suit you. If you're struggling talk to the group leader. Perhaps you need something more structured?
I know plenty of people who adore the 5:2 because they don't have to think too hard, it didn't work for me.