Background info: my DC is in yr 8 of a highly selective grammar school (let's leave discussion of the "evils" of selective education for another thread).
School currently runs GCSEs in the usual 2 year period, from yr 10 to 11.
Another nearby grammar school is switching to GCSEs in yrs 9, 10 and 11. So there is now talk that we too might move over to 3 years for GCSEs.
Our nearest comprehensive schools in the area already do this too.
If parents are consulted in such a change, instinctively I would prefer our school to stick with 2 years. My reasoning is that I (and my DC too) would prefer as broad a range of subjects to be studied for as long as possible.
I don't agree that young kids in yr 8 should have to decide on GCSE subject choices, whether because of lack of experience or personal maturity (sometimes a personality clash with the teacher might put you off a subject, another year with a different teacher could change your opinion entirely).
And absolutely in our school (hoping to not sound too arrogant) these kids have already gone through a selection process (however faulty) that indicates their relative academic ability, they should all generally achieve well so why would they need an extra year to cover syllabi designed for 2 years?
As I understand it anyway, with some subjects like science and maths, they are already covering GCSE level topics before yr 10.
What has been your experience of 3 year GCSEs? What are the advantages for your kids? And disadvantages too?