To me, kilometers and miles are in a similar class; I don't have a reason to prefer one over the other. Same with kilos/pounds. Even though a kilo is more than double a pound, it's used to measure the same kinds of things. As with Centimeters/inches, quarts/liters, yards/meters.

Metric seems to do better at measuring very small things, or very precise things, but lacks middle measures that help with day to day life like Ounces and Feet. If there was a metric foot, like a quarter or third of a meter, it would be more useful. Same if there was a metric ounce, lets say 25 grams (an actual ounce is slightly over 28 grams).