I didn't bother reading all the way through to places like grade 8, but looking around at lower grades it looked quite interesting; the general technical and aural stuff looked different, challenging, and often quite useful. I always have mixed feelings when I look at an exam syllabus because I'm a bit old, busy, and limited in my interests, so although I think it's completely right that they've put all the extended techniques in there (if you're going to claim to be a recorder player, you should be able to play the recorder, at least at some level, in all its styles and appearances) - although I think it's right, it's not of great interest to me because I don't tend to stray outside early music. For the same reason, scales with innordinate amounts of sharps in them are of little interest (I'd only meet them in violin music, where I'd probably find myself subtracting three sharps and playing in a pretend bass clef anyway; which is why I ought to get to grips with music in more flats, because at the moment if it's 3 flats I find myself with six of the things, panic, use C-fingering and hope it doesn't go too high).
Yes, OaG you're right, music isn't really comparable to other subjects. A lot of academic subjects, if you put massive effort in and have a fast-learning brain, you can get up to A-level reasonably promptly. Music has a whole area of manual skill that I don't think happens so fast. To be honest, I think that's part of music's charm; since hurrying the manual side of things doesn't seem to make it go any faster, it means you can play a lot, enjoy, take your teim (at least I can, I am an amateur with no target to meet), and get better at whatever rate works for you, while enjoying all the music you play along the way.