These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Some hardcore Dragon Ball Z fans have denounced Kai as dishonoring the original series by removing much of the character inherent in the extended stories, while others enjoy the much faster-paced plot.
People who grew up watching FUNimation's original Dragon Ball Z dub decry Kai's change of dialogue (even though Kai's dubbed English scripts are far more accurate), the changes in voices (even though Kai benefited from Sabat, Schemmel, and company gaining a decade of voice acting experience since the original dub), and the loss of Bruce Faulconer's music (which was intensely disliked by fans of the original Japanese DBZ back in the day).
The news that The Ocean Group is in the works for a Canadian broadcast release has threatened to start up the Ocean vs Funimation war once again.
All of above is taken Up to Eleven with the Latin American viewers. Unlike North America, we only have one dub, and it was perfect. After Kai shows up, well...
Nappa at one point said he hates the media in the Abridged Series, he actually says this line in the show, making this a possible case of Ascended Fanon.
Narm: Sure, Gohan's screams are properly full of emotion... but some of them carry on so long that it loses the intended effect.
Superlative Dubbing: The English dub is close to flawless, since most of the actors have been voicing these characters for over a decade.