Yeah with AQA and Edexcel, the content is the same. In fact, i read on a website that with this current maths syllabus, all exam boards are required to teach the same content (something which has never been a requirement in the past). Obviously, this excludes OCR MEI since that spec was designed in with MEI.
I do Edexcel and in terms of assessment structure, it is clear what content each paper tests since for AS there is one paper testing pure mathematics and paper 2 testing the applied maths (stats and mech).
For the A-level it is 2 papers on pure mathematics and the third being on stats and mech.
For AQA, i am yet to try out any of the AS papers so i dont really have an opinion on what the style of assessment is like....