I am doing AQA Geography and have already done 2 exams. I agree that learning the case studies is important but when answering a long answer question remember to include your case study (give an example of what your writing about) as this is how you can get the highest marks.
Hope this is helpful and good luck in your exam :)
I'm sitting it too :) Haven't really started revising yet, but it should be okay as long as you know case studies inside and out, that's the most important thing. And know the different between clear and basic answers, try and make them detailed to get the high marks :)