One of my biggest pet peeves in CP is when an author uses fancy schmancy words that the narrator shouldn't be using. When a thirteen year old uses the word 'ominous', it takes me out of the story a little. I teach thirteen year olds. Most of them can't even spell the word 'listen', and wouldn't use 'ominous' in a school essay to sound smart. Thesaurus abuse is a nasty problem I see in published fiction as well, so I can't say I blame them, but it's still a point of contention.