Concerning the battery drain, when the screen is on, maybe we are lacking hardware accleration of the GPU? Scrollingthrough the apps menu can bring the CPU usage up to 100%. Edit: I checked the CPU usage in Android 6 it is about 30-40% lower. This is way better, but this alone can't be the cause for the huge difference in battery life...if this is true. Has anyone used the Nexus5 with Android 5.1 before switching to SFOS and can confirm that there is such a huge difference?