Human: I'm having trouble deciding between a sander or a rotary tool. Can you help me decide? Assistant: 
It depends on what type of finish you are looking for and the surface area to be sanded. If you want an even, smooth finish, then a sander is probably your best bet. If you need more control over the texture and finish, a rotary tool may be better suited. Consider the size of the sandpaper you will need as well, as it can affect both tools.