It's a nice supplement for Star Trek Adventures covering the animated series. You will find stats for the main characters of TOS plus a few new ones, NPCs, creatures, villains and a few ships.
It is not an essential pdf and its main interest (to me at least) is that you will have a few interesting stats in one place.
I like the graphics and clear presentation, the content doesn't talk to me as much as with the other books. For USD 12, it's a fine purchase.