I did o levels in 1983 and my son did gcse this year , 2019. Maths and science seemed easier overall, though I think the syllabuses have widened. I did calculus at o level and the gcse equation questions and trigonometry seemed a level down from what we did. English was taught with far more rigour (& much better taught all through secondary) but perhaps that was my school underperforming ) at the end I think the level of difficulty was similar. The gcse humanities covered more ground and while similar in difficulty the syllabuses were scarily large - so harder I think. Languages seemed to have got significantly easier, though my son didn’t engage here so perhaps to get a good mark you’d have to actually work, he got a 5 with very little work or revision throughout 5 years of study. And he got the opportunity to study more subjects than I did from a much greater choice of subjects, which was great. I do think having to cover all 3 sciences to gcse is a big forward step, I dropped one which I have always regretted. There seemed to be huge amounts of spoon feeding now , school providing reams of printed revision notes and work books, and on-line revision resources, while we had none of these and had to rely on our own notes, though we did have much better textbooks, which were possible I suppose because of less change in the syllabuses year on year. I had no target grades, much much less individual feedback, much less exam practise, no pressure really apart from that supplied by myself and family, but also far less supply teaching (which in my son’s case got to a level in a couple of subjects that was detrimental) and my teachers varied more, one or two brilliant, but equally one or two poor, my son didn’t have the poor ones, but also seemed to miss out on the really good ones, everything was focused towards the syllabuses and the end exam goals, it wasn’t like that at my school, in maths for example we worked through text books, the syllabus was not mentioned directly, though I’m sure the text books covered it thoroughly as we got reasonable grades, some people got a long way and were helped along well by the teachers, some didn’t get far and no one was much bothered, exams were rarely mentioned until yr 5 (now year 11). Both my son and I went to large comprehensives.