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.
YMMV: The Spellbook
Base Breaker: Matt. Some fans consider him to be a viable supporting character and well developed in his own right. Others consider him underdeveloped and a wasted character due to his extreme lack of screen time to work with.
Kennedy is also often unfairly compared to Matthew Ryder of the Tale of the Valkyrie series, due to them sharing the same basic role (Spouse to Meg). Both Ander Arias and Jerry Peet (Author of Tale of the Valkyrie) consider this unjust criticism as the two characters have vastly different origins, storylines, and roles in their stories. Kennedy is a support character and comic foil, while Ryder is the titular protagonist.
Fan Dumb: Kennedy is often called an Anti-Sue by viewers due to his empty character design (he shows personality only when absolutely necessary), despite an Anti Sue being a character who is depicted as being horrible at everything they do, everything they attempt, and everything they're involved in.
It's Not Supposed to Win Oscars: many people said that this story lacks depth and complexity. Even if that's true, the author stated that the story is only attempting to be funny.