In a skill-based game, it's harder to tell if a companion gives you the skills you are looking for, especially before you recruit them.
This looks like an advantage to me, not the opposite. Share the work of explaining about the role/skills of a companion to the narrative elements, a guy with a scarred face with a 2h battle axe can be as informative as a class "Berseker". And that could hide some not-so-obvious skills so we can have a bit of a surprise later, while with the class system we have direct access to all that information, not a lot of immersion here.
Update #12: Reddit Q&A with Tim Cain
in Pillars of Eternity: Announcements & News
Posted
This looks like an advantage to me, not the opposite. Share the work of explaining about the role/skills of a companion to the narrative elements, a guy with a scarred face with a 2h battle axe can be as informative as a class "Berseker". And that could hide some not-so-obvious skills so we can have a bit of a surprise later, while with the class system we have direct access to all that information, not a lot of immersion here.