In its uncollapsed state, wherein you actually use the mouse, the Arc Mouse is not quite as clever. It works well-enough as a basic two-button scroll mouse, but the extra left-side button complicates things. If you hold a mouse in a standard grip, with your palm resting on the tail-edge, it becomes impossible for your thumb to reach the Arc Mouse's side button without contorting your hand. Situating your palm on the top of mouse (aka claw grip) solves the problem, but at the expense of precise cursor control. Holding the mouse thusly, we actually had to think about positioning the cursor over Windows' familiar close, "minimize," and "maximize" icons.
We agree that's a minor quibble. The side button isn't exactly crucial, and the core "mousing" functionality works as you'd expect it to. We also like that setting up the Arc Mouse is so simple. After you insert the three, Microsoft-provided AAA batteries, you plug in the USB receiver, wait for Windows to recognize the mouse, and reboot. Mac setup is even easier, as Mac OS X found the mouse as soon as we plugged the receiver in. For its intended purpose as a travel-friendly input device, the Arc Mouse does exactly what it's supposed to.
