Nice quality Optimus for those who can't afford a real one.  There are a whole bunch of differences in this two which makes it a "variant" of the real Optimus.

The bootleg has light blue die-cast feet and different stickers.  I ripped the stickers off of the trailer because they were really ugly, anyone who owns this toy knows what i am talking about.

Bootleg on the left, real one on the right.  Roller needs Diaclone men to pilot him!

Different stickers on the inside and outside of the trailer.  The bootleg's gun is different.

bootleg on left, real one on the right.  Bootleg has different smokestacks, a larger front grill, a different silver strip, a different bumper, and the word "truck" in between the wipers.