+1 rechargeable batteries
still prefer hardware mouse/keyboard myself, mine, the 1600 dpi is too fast so i have to use the 800 setting, have not figured out how to get the mouse speed to 50% so i can use 1600 and benefit from the setting on the mouse
i cant stand my moms mouse, the wheel is just a pita to use, moving it only 1 click is near impossible, and it scrolls too easy when i try to middle click so i miss the target 1/2 the time
A trackball doesn't need a mouse rink.
You can use a trackball on a moving vehicle (e.g. a ship) and fasten it to a table so it doesn't fall off when the ship rolls.
With a trackball you can use momentum - spin it and let it run.
I prefer trackballs, but I can never find one when I need one, and I haven't even heard of a Bluetooth trackball.