A recent example is the change in MBP battery life with Lion; check the first bar chart in http://www.macobserver.com/tmo/article/os-x-battery-life-analysis-fro

A recent example is the change in MBP battery life with Lion; check the first bar chart in http://www.macobserver.com/tmo/article/os-x-battery-life-analysis-from-snow-leopard-to-mountain-lion http://www.macobserver.com/tmo/article/os-x-battery-life-ana....