A poster named Sizzle at TFW boards posted a review with pics of Thundercracker in comparison to the official Henkei version:

http://www.tfw2005.com/boards/transf...ml#post5366906

Summary of differences:
-Very hard to tell its a KO while MISB. The only way is to judge from the alignment of the decepticon symbol on the wings, which differ from the official one.
-In robot mode, the knees and shoulders on the official one have a slight notch compared to the KO which has none.
-Another difference is that the missiles actually fit - although one side is slightly loose.

Having said that, I am weak and ordered a set of the seekers.