Do you want to see the good guys get beaten up and destroyed and crushed with not a chance of victory for over 40 minutes? Then I've got the story for you!
I mean, it's alright, it's just not exactly the most rewarding story since it's completely pointless when the show itself establishes everything this movie much more succinctly. And this is Dragon Ball Z we're talking about; ain't nothing succinct about this show.
Sadly, the fact that Trunks's origin story was pretty well-covered in the show itself renders this superfluous. Unlike the other TV special with Burdock, the Trunks special adds no new backstory and exists mostly for the fight scenes. And unlike the theatrical films, it sadly doesn't have much more of a budget than any random TV episode. So it's decent, but it doesn't really need to exist at all.