I honestly just read part one, then skipped to the current chapters (I think it was when they first started on the island to get Naruto the Kyuubi's power). I feel like I missed little of consequence besides things to facepalm/laugh at that I've read about through juju debathes and such (Pain arc; Kakuzu being beaten by repeating the same thing; Sasuke's bs against Deidara).
I actually went and youtubed some of Tobi's shenanigans to understand how Madara is worse too, but overall the characters and general mission to get Sasuke back is still the same… And of course, it's still clearly worse even skipping along to this point, mainly due to it still being focused on rescuing an unlikeable character...