Keef,
The JAA IR would take a finite proportion of the time left to me. I don't have that sort of patience or dogged determination.
The FAA IR I did in two weeks
I have no FAA experience whatsoever so I might be way off the mark, but as far as the knowledge or skills level that need to be demonstrated for the successful issuance of an instrument rating, I don't believe they vary significantly between those two agencies. The exam schedule and presentation, one might well be more convenient/better thought out than the other, but other than that, is it possible that it is purely a matter of perception more than anything else?
After all, there is a consensus amongst those of us who hold JAA IRs that by and large its alleged difficulty is grossly exaggerated.
I get tired of posting this time and again, but I do it anyway in case it helps persuade anyone that an IR really is within reach of the common PPL.