thought I would throw my 2 cents in here

with my eldest and youngest it was simply when they were dry overnight. My eldest was 4 when we stopped and the way we did it was to not buy any nappies and just run out one night.. We told Ethan prior to this that when we ran out that was that.. With Isaac and Jacob we were a bit lazier as they wore the same size nappies.. So we just stopped buying them last month and did both at the same time. Jacob who is younger was always waking with dry nappies where as Isaac who is 4 would always soak them.. But Isaac hasn't had a wet bed where Jacob has..

I think it would just come down to how prepared you are to have wet beds at night. and if DS has dry nappies over night.. always give it a trial run for a week which is what we did late last year but neither boy was ready so we went back to nappies