most people would opt for 7 written exams rather than a single exam on the entire syllabus followed by a 1-2 hour oral, where presumably (I haven't taken an FAA test so I don't know) you couldn't just get away with guessing the answer
I think that's true, because it breaks up the revision. In terms of total swatting time there probably isn't much to choose between the two.
I know that myself, as a pilot who "should know the basic stuff from flying around" would now find it much harder to pass the JAA exams than passing the FAA one. The FAA PPL written is largely what most pilots would call common sense.
In fact a clever FAA PPL/IR N-reg owner with a lot of hours, a good tech brain and an interest in tech flying matters should pass the FAA CPL exam without any revision.
The FAA manages to deliver a solid ICAO compliant license (PPL or CPL - or indeed the ATPL which is still one book about 40mm thick, compared with ~ 700mm of paper thickness with JAA) in this way. Why doesn't the JAA do the same? I have never seen an objective analysis on this, and everybody I've met - airline pilots included - flying in the system just laughs when they recall what they had to learn.