Thanks guys, and I do remember discussing these differences, but I thought you were referring to some substantive differrences that I had missed? I think the fact that there appear to be no obvious differences is a good thing and indicative of the overall soundness of the design, I did note on the J-31 thread that the Air Force Magazine had commented on both of these advance tactical prototypes and their likely usages?
Where can I get a glance at this particular piece from Air Force Magazine?