I do not think it can be accentuated enough that the IGCSEs are more rigorous than the GCSEs taught in most schools.
Apart from a few prestigious private schools, the majority of schools only offer GCSEs.
It is disappointing that such distinctively different courses can be regarded as equal by further education colleges, state schools (who were not granted the funding for them), some Universities and other areas of education.
Using science as an example; if one finds this subject a challenging one, then they can opt for the 'double award' GCSE in school instead of the more ambitious 'triple award'.
I came across this extremely informative article on the intensity of the IGCSE Sciences;
and it reaffirmed to me just how incomparable they are to the GCSE.
In hindsight I wish I had urged my son to not battle through these three exams, but to have been content with one science (he took IGCSE Biology a year early) and concentrated on the subjects he excelled in instead.
A friend and fellow home educator, Sam Martell, is devising the Double Award Science (and also the Triple Award) IGCSE course for home educated children.
She explained to me it is not as intensive as sitting the three single IGCSEs and the Edexcel board only has two papers. This sounds more accessible (although still challenging) for the student who is keen to study the sciences but has no grand ideas for studying medicine!
For those who are dedicated towards a medical career, then the single IGCSEs would be a valuable prerequisite to further studying.