The NRT Suite lounge by the 40s is a decent place to do some plane watching (though the UA lounge was awesome for watching takeoffs yesterday.) I wouldn't show up particularly early for it though, as it's pretty small and crowded during the 11-12 rush of US and European departures. Right at 12 though, I was literally the only person sitting in the lounge.
Food selection is merely adequate for a quick bite - but I'm fine with it considering the feast that was coming up on board.