non-US PhD's with extensive course work
I have a PhD in theoretical physics obtained in Germany: in particular


  GRE is not compulsory, but might help to improve the chance of getting an admission.


GRE is totally irrelevant.


  We will know the research area in the beginning.


this is mainly true all across Europe but however there are some departments whose research projects are to be decided on your way throughout graduation (it happens in Italy, for example). I had a very strict and detailed project to fully adhere to, but it might not always be the case (with corresponding advantages and disadvantages). Also notice that sometimes, for whichever reason, PhD students change projects along the way (mostly because they do not like it or because it is a dead end line of research).


  Most seems to have no course work or little course work.


Wrong. I had heavy teaching duties (three-four semesters), mandatory classes to attend and corresponding exams to take (it happens in other European countries too). Besides that, compulsory seminars and conferences to take part to.

As a general rule always determine with the department you are applying to what the local rules are: it is very department dependent and even in the same department different scholarships may get treated differently and have different loads. I would personally go for a research project I like and then manage the extra curricular activities accordingly: after all, the chances to get a position afterwards will only depend on your final PhD thesis (and related papers); nobody ever looks at the exams marks and classes you have taken.