It really depends on personal taste and preference, but I just want to put in my opinion.
The 25G looks good in some poses and angles, but sometimes I don't like it for the loosing crouch piece, floppy armor parts, short neck (not a problem to some I know, but to me they are too short to look good), and on some units they have different shade of blues.
I generally have no complaints on the 1J, it looks crispy and sweet to me. I am not too excited about the Super Parts though... The 1J is already beautiful in its plain mode.
P.S. Usually you buy both at the end. So don't think too hard.