There is no official line - but a quick search will show that different people consider it to be equal to any of the above.
Personally, in terms of difficulty I don't think anything is harder than a science O level (and since we are constantly assured that GCSEs are not getting easier then the same stands for that).
There is a lot of volume to learn in things like Air Law - but that is nearly all simply memorising stuff.
All the exams can be done from start to finish in less than a year whilst holding down a full time job - to give you an idea of the amount of study.
So in terms of difficulty
andquantity I would say that all the exams together are about the same as a couple of O levels.
There will be many differing opinions to follow.....
If your question is as to where to list it on CVs (BTECs in the A-level box or whatever), then aviation employers know what it is and non-aviation employers probably won't care a jot.