I AM FAA CFI-CFII-MEI AND ALSO JAA FI SE AND ME.
FAA IS VERY DIFFERENT FROM JAA.
UNDER FAA WHEN YOU TAKE DUAL IF YOU HAVE THE RATING FOR THE AIRCRAFT YOU CAN LOG PIC, SO ALL YOUR TIME WITH FI AFTER THE PPL EXAM YOU CAN USE IT AS PIC FOR THE ATPL FAA, ALSO YOUR PIC UNDER SUPERVISION YOU CAN USE IT AS PIC TIME FOR THE FAA.