1. There seem to be a very slight delay in the response of the scroll wheel after the mouse is left idle for about 30 seconds. This could be due to the Smart Sleep Mode of this mouse kicking in. If this is indeed the reason, there is no way to configure how much idle time before Smart Sleep Mode kicks in.
2. There is a delay of about 4 seconds or more (for Bluetooth to reconnect) when turning on the mouse before it becomes responsive and functional.
3. Occasionally disconnected from Bluetooth and does not reconnect back immediately. Take sometime before it re-establish connection. This could possibly be due to battery power. This mouse seem to consume power quickly.
4. In Cinnamon 2.8.7 which I am using, battery status does not show up in Battery Applet, Power Management, or Power Statistics.