I read this interview with Lars on Blabbermouth:
On whether the songs are punchier, four or five minutes long:
"Well, the most of the intros are four to five minutes. I don't know — METALLICA and short songs just don't go that well together. But whereas 'St. Anger' was an exercise in over-pummelling the listener, these new songs echo some of our stuff from the '80s — long, epic journeys through different musical landscapes, heavier, but a lot more melodic."