Estyn's call for small sixth forms to be merged reflects the inspection agency's failure to understand how rural Wales works, according to headteachers.
The agency says pupils are missing out because small sixth forms cannot offer a wide range of vocational and academic courses. Only those with particularly high standards or bilingual provision should be maintained, says a report published earlier this month on post-16 provision in schools.
But in Ceredigion's Teifi Valley, there is little support for the proposals.
In common with most of rural Wales, its secondary schools are small and spread about, so any creation of "super" sixth forms, as Estyn suggests, would mean more travelling for many pupils.
But long bus journeys are not the only gripe. At Dyffryn Teifi, a Welsh-medium secondary in Llandysul, head Dorian Williams has 100 sixth-formers, well below the Audit Commission's 150-pupil definition of a small sixth form.
He believes losing sixth forms would drive away the best teachers, who enjoy working with older pupils. And it would destroy the family support that he thinks is central to personal development during these final school years.
"Estyn's report reflects how it fails to understand how rural Wales works," said Mr Williams.
"Perhaps it's relevant to small sixth forms in large towns and cities, where there could be closer co-operation between different schools. But in this part of the world we are working with local colleges and using video conferencing to bring sixth forms together. We're committed to both vocational and academic courses."
The main thrust of Estyn's report is the quest for greater pupil choice.
School sixth forms normally offer 16 A-level programmes, compared to up to 40 at FE colleges, which also have more vocational options.
But Mr Williams believes schools are capable of offering that choice. His sixth form has 23 courses. Some, such as building, are run in partnership with the county's only FE college, Coleg Ceredigion. Pupils who take the course travel to the Cardigan campus 45 minutes away.
Video-conferencing facilities are used for an electronics course which is taught with the help of Anglesey-based schools support service Cynnal.
Catrin Davies, 17, who will be starting her final year in September, said:
"You know teachers well enough to understand how they want you to work."