Apart from the fragile electronics and its sheer size, this figure hasn’t got anything to offer. This is a real shame, because it makes sense kids would want to go rough on their human figures and vehicles with a large Rex figure, causing mayhem and chaos as Rex did in the movie. The TLW line applied a more clever approach and delivered two large Rexes, one with electronics (in better condition than found in the Red Rex) and another poseable one without them for playing wild with.
As a side note, some advertisements as well as various card backs of other JPS1 figures displayed a large Rex sculpt which was completely movie accurate compared to this final Rex sculpt. This particular Rex figure was one of Stan Winston’s Rex models, used as a stand-in to show Kenner was developing a large roaring and biting Rex figure. This brilliant Rex sculpt was never intended to be the final big Tyrannosaurus action figure of the JPS1 line (at least, no proof of this exists).
It is popularly believed that this was a sub-adult due to JPIII size charts giving lower size estimates than that of previous size estimates given to of the franchise and because it had a brighter coloration than that of the Tyrannosaur Buck, a fully grown adult male. However, there are problems with this theory. Regarding skin color, every tyrannosaur in the films has their own unique skin color and the Tyrannosaur Doe, an adult, has lighter colored skin than Rexy who is an adult as well. As for size, size is inconsistent in the films and their supplementary material. Furthermore, since there has been no official source found or released thus far that confirms that this individual was a subadult its smaller size could be something else instead of just simply being a subadult. It can be noted that size can vary within a species and that there have been individuals of a species that can grow smaller or larger than the average size given for that said species.