This is mostly in response to Mattz.
I like the new turn that the series is taking. I typically hate the "warrior who doesn't fight" thing just as much or more than the next guy if it's not done well (for example, I did not like the "warrior who doesn't fight" ideal in Trigun. It was poorly done). On the other hand, I think Vinland Saga is much more refined than any other attempt at the ideal I've seen.
Vinland Saga took the reader on a journey before arriving at the ideal, as opposed to the character having it from the start and having the reasoning explained. All throughout Thorfinn's life, he basically wanted nothing but revenge on Askeladd, fueled from his hatred. Eventually, Askeladd was killed, and not by Thorfinn's hands, which essentially destroyed Thorfinn's purpose in life. If you understand this, I think it makes the farmland saga a lot more interesting, at least that's the way that I see it.
To be honest, I was a bit worried that Vinland Saga would boil down to Gungrave-like plot where the main character seeks revenge as the point of the story. If you can't tell, I disliked Gungrave. If you didn't watch Gungrave, then you can think of Thorfinn as Sasuke from Naruto (oh God do I hate that character). I was very happy when Askeladd died by someone else's hands because that meant that the story of Vinland Saga doesn't have to be stuck in the dark ages of a revenge plot.
That being said, I'm actually very interested where the author is going to direct Vinland Saga in the future. I think that if you dislike Thorfinn no longer being a Sasuke-like nothing-matters-but-revenge character, then you probably shouldn't read Seinen, and should stick with mindless action-Shonen mangas like Naruto and Bleach. Not that those mangas are bad, don't get me wrong. I like those mangas as well but they're more geared towards exactly what you're looking for.