I was on this exact same flight in january this year. MSP-LAX-SYD-LAX-MSP.
I don't have much to add to what everyone else has already said. You get pajamas!! and yes you get fed. I missed out on the snack, because I was sleeping, but my wife said they put out a snack cart and told her to help herself....she of course left me sleeping and didn't get me any dang snacks!
We got fed pretty much right away after takeoff. I ate, watched a couple movies, and slept for like 8 hours straight.