The Ergo Mouse's precise control was also not helped by it's poor tracking abilities. Whether it was the sensor (we suspect it is, as it's just optical as opposed to laser) or some signalling problem, we're not sure, but every now and then the cursor will just stop responding or become slow and jittery in its movement. Like the speed of movement issue, this will probably be a minor problem to slower computer users but if you're used to interacting with your computer quickly without having to think about it, it will be a major annoyance. It's also not the smoothest mouse to slide around thanks to some very small glidepads.
Further problems stem from the lack of a scroll wheel and general dearth of buttons. This mouse does have the essentials in the form of a rocker button, which sits under your thumb and acts as your traditional left and right buttons, and a large button that runs down the front of the joystick that emulates the middle button (normally used for scrolling). But without a scroll wheel for small and quick scroll movements or forward and back buttons for traversing pages in a web browser, overall navigation can feel limited. Of course, we can see the logic that more buttons, and particularly a scroll wheel, could make the Ergo Mouse more difficult to use and possibly even counter its benefits, but to have such a lack of functionality is going to be a major problem for any serious PC users.
As for other features, the Ergo Mouse is available in two versions: Large (EM550GPL) - which we're reviewing here - and Small/Medium (EM550GPS). It's a wireless device, too, so if clutter is a concern that's a plus point. It also seems well built with a sturdy, solid feel and a smooth, soft-touch finish all over. On the underside is a battery compartment, an On/Off switch, and a button for syncing the mouse with its included USB receiver. Two AAAs are needed and some basic ones are provided in the box.
Comparing the Ergo Mouse to alternative RSI reducing mice, it's definitely a difficult one to call. While sculpted conventional mice like the Microsoft Natural 6000 provide better tracking and have more functions, they still aren't quite as comfortable as the joystick design. Trackballs are also a possibility and again can offer better accuracy and more functions but can be uncomfortable as well. However, generalities aside, this particular 3M Ergonomic Mouse just doesn't quite cut it. The tracking isn't good enough, it has too few functions, motion isn't smooth enough, and it's just a bit too expensive.
The 3M Ergonomic Mouse is one of the most effective anti-RSI pointing devices we've seen. Its design ensures your wrist and arm are in their most comfortable position and the button arrangement is also very comfortable. However, its tracking isn't great, it's slow to use, and even though you should put your health above all else, we think it's a bit too expensive – just get up and take a break regularly.