Ones that I know of:
Kranix missing head
Duplicate planet shells
Duplicate planet teeth
Duplicate rings
Loose joints & door hinges
Something that bugs me about the robot mode generally - He has green eyes but red LEDs behind them. :mad:
As a display piece, he's awesome. For the OCD collector or someone who plays with their toys, pray very hard you get one of the good ones. Probably better off saving for the Takara release really!