They all do, but you can't give it a 'close look' because it is entirely use dependent. MY Google Now will not be the same as YOUR Google Now. If you're worried about battery consumption, you can disable location history. You will get much better battery life (and not so much drain from GN) but you miss out on most of the 'magic' that makes Google Now Google Now, like timely traffic/weather cards and suggestions for nearby stuff.