I would have to respectfully disagree. The entire point of background app refresh is not that the apps would now run in the background, but that when you went back to that app the information would be more current than the last time you viewed it because it was updating in the background, not just running in memory. An app running in memory will only do so until the system needs that memory. Make this test: turn off background app refresh on a given app and leave it open in the background but don't go to it for a few hours as you continue to do other things with your phone. When you do open it, you will notice it updating itself before displaying information (social media apps or Mail apps are best for this test). Take note of how long that process is. Then, the following day, turn background app refresh on for that same app and repeat the process. The app will not take nearly as long for the new information to load due to updating itself periodically in the background. To assume that this background app refresh process does not use more battery, however small it may be, is ludicrous. It simply has to use at least some battery as all processes on a phone do.