Another difference is that sitting ground exams under JAR's the questions and answers have not previously been published for public consumption, i.e. in Europe the first time we find out the exam questions & answers are when we're sitting in the examination hall.
Putting it another way, i.e for those who don't know the FAA system. When you do the ground exams under the FAR's they very kindly publish all the exam questions AND THE ANSWERS to go with them. All you've got to do is to memorise which answer goes with which question, and you should pass - all of which I found a bit of a no brainer ( certainly when compared to UK CAA 'penalty marked' CPL & ATPL exams of the mid 80's ).
See:
FAA Airman Knowledge Test Question Bank
That said, I've always wished the the JAA would publish an equivalent to the FAA
AIM and I wish the JAA could come up with a web site that's as easy to use as the
FAA's
Ah well, 'Vive la difference' - as they say in France.