The text is written in a straightforward tone, but you'll discover the main characters personalities through the annotations they left in the margins. There are few choices (though they impact large chunks of the text) so it's still pretty linear, and thus a very good introduction to IF.
For a peek behind the scenes, there's a really interesting post by Liza Daly on how she conceived, implemented and refined her annotation system for Harmonia.
@lertsenem Found this thanks to your suggestion! Awesome game!