Have you checked out any of the AARs or Lets play videos?
In terms of difficulty its on the lower end of the scale, though it depends on a lot of factors such as which nation you play.
If you mean complexity it is one of the less complex PDS games.
Its a cross between EUIII (economy, diplomacy) and HoI3 (cmbt).
The warfare mechanics are where the game shines... they are more detailed than HoI in some ways (land), but less so in others (sea).
My sig should have a link to aar I was writing.... with some luck Im in the mood to start working on it again. Maybe this weekend.