If my device supports the native format of the content, I definitely want it decoded there rather than transcoding on the server. Assuming said format isn't significantly more power hungry than the transcoded codec.
Sure. But they’re not giving the user a choice in the matter. Also, it’s transcoded on the device as it’s backing up, which is the last thing I want to spend battery power on. My NAS is on and plugged into the wall 24/7 for a reason