Android is a complex operating system built for multiple things and purposes, not just audio, audio has been put on the back burner in most instances in Android, it's great there's this and other devices being built but yes booting the device will suck some battery juice, more than idle.
I think as they update android and Sony release android 5, that will make the battery last a very long time in standby, I just hope Sony back this device up with quick and constant updates. Especially for the price, and lack of compatible connectivity.
Really? Power down drains more than just leaving it on? Why doesn't Sony mention this in the manual? They talk about everythung else sucking battery, like EQ.
Maybe rebuilding the library is also a drain factor? I can't completely avoid the screen. Searching for an album takes some time. My first charge showed screen was on for 2.5 hours because I was learning how android works, but now I try to keep it to a minimum.