Canon debate in regards to the comic spinning webs and webs of details that are never in or referenced in the movie. Like the history of the Narada vs what's in the movie and on the DVD special features. Nero and Spock's relationship in the comics vs the film where it's implied Spock had never met Nero before the supernova destroyed Romulus. Also the ENT-E crews involvement in the fiasco and lastly the timeline of Spock leaving for Romulus in the comic vs what we see in the film.
Canon debate as in how much of Countdown to Darkness will be a legitimate prequel to a film vs it being a fanficky project done with limited involvement from the film's writing and production team.