"Dreadnought" is remarkably similar to "Prototype" as a vehicle for B'Elanna Torres, but succeeds where its predecessor failed by making the story relevant enough to the character where its fairly generic plot actually fails her.
Episodes like this were easy to do with B'Elanna, because she is fantastic no matter what (to put it bluntly), and putting her in peril was one solid way to bring out the best of her. Oh, and the particular peril is a Cardassian weapon she modified that has also landed in the Delta Quadrant, and she must now disarm.
The fact that it ties into her past, which for the Maquis members of the crew can sometimes be a little vague (who seriously wouldn't have preferred to see Chakotay in his prime rather than his contentment?), adds that extra element that makes it more a success than a relative failure. Sure, most of that past is glossed over in favor of the increasing peril B'Elanna faces trying to deprogram the weapon (the Deep Space Nine episode "Civil Defenses" is the version of this episode done absolutely right, by the way), but it has just enough significance for a shot at redemption.
"Dreadnought" is not an episode that I would recommend to skeptics, but it's easily one that existing fans can revisit at their leisure, to see whether it truly fails or succeeds. It's one of those episodes.
franchise * series * essential * character
Memory Alpha summary.