I've heard several people complain that the translation process was unreasonably quick. I think people are missing a line of dialogue, which might have been part of Jeremy Renner's voice-over segment, where it's said aloud that it will take a few months to get where they need to be. This is after they've already been working on it for a week or two, it seemed. When action resumes, I was assuming that a few months had, indeed, passed.
I wouldn't have minded if they showed more of the linguistics stuff, because they made it interesting to watch, which is a feat unto itself. But I think there was enough of it to get the point across, and no more. Arrival is a lean movie that way. It takes its time easing us into the situation and onto the ship, but even that initial chunk feels purposeful and focused.