That's the third blunder the AQA exam board has made - two AS-level papers (including one I sat) and now a GCSE paper. I think the problem with them is they focus too much on their presentation and image, and don't spend enough time verifying the content of their exams! They are obsessed with useless jargon like "don't infringe the rubric". They can be overly wordy with their questions as well.
They have made some really dodgy papers in the past - I remember taking a biology one at GCSE that was all about the environment - covering a tiny part of the specification. However, they tend to be quite lenient when they set a bad paper. It does vary between subjects though.
Edexcel seem to care less about exam presentation, but they seem to be more strict with grades in essay-based subjects, even if the content is hard. I have only done three exams with them, so I couldn't tell you more. I've heard from a lot of people that OCR seem to ask clear questions.
However, I did AQA GCSE Geography last year - it seemed a lot harder than this year's (new) syllabus apparently the old one had been going since 1989, the coursework investigation took forever and was by far the hardest piece of coursework in GCSEs, for me at least! It actually really tested you. Put the effort in and got an A*, so it was worth it!