You don't have to go across town. You use it to get to know the good stations in your area, and then you just go to those regularly when you are nearby.
Also it's good to just quickly survey the stations when you need gas in an unfamiliar place. Obv you don't drive 5 miles down the road for a better gas price, but if they're all within a 0.5 mile radius, you can grab the one which is best.