If it's anything like Cambridge (which I should imagine it would be), once you've done the refeed, you should be back to 'normal' (though watch carefully!).
So, if Slimming World worked for you before, there is no reason why it shouldn't work again :clap:
Having said that, I have nothing against SW, but for the rest of your life
I think that would be tough.
With diets such as those that give you free foods, there is always a high penalty to pay for others, even other healthy foods. Would you want that in maintenance?
Another thing is not being able to see the syn value so easily on items you want to buy. You would need to keep your 'book' by your side forever more.
I would highly recommend using some form of regular calorie counting myself. Virtually everything has the calorie value on it so it's easy to make quick decisions. You also get to practice portion control, can eat a variety of foods and experience 'normality'
Doesn't mean you will be calorie counting forever. Once you get the hang of it, you can see at a glance whether something highly calorific will need a lower calorie rest of your day (if you know what I mean), but you will be able to get a good balanced way of eating that will see you through forever more :clap: