With three fingers, you get macro-level commands. Swipe up to display a screen with preview windows of all currently open applications, from which you can simply click on one to select it. Swipe down to hide everything and return to your normal Windows desktop screen.
Those three gesture groups represent the full complexity of the Microsoft Touch Mouse. The only one we don't like is the thumb-side forward and back navigation. It's responsive enough--all of the gestures are, really--but you need to tuck your thumb in a way that feels awkward. We'd rather have hard forward and back buttons.
We can also report that the Touch Mouse works well in varied Windows 7 environments. We tried it with a single display, a dual monitor setup in extended desktop mode, and with an all-in-one with its own built-in touch support. The Touch Mouse worked without a problem in all cases.
The primary competitors to the Touch Mouse are the Apple Magic Mouse and Magic Trackpad, and the two implementations are very different. Apple's touch devices heartily embrace touch, the Magic Trackpad in particular with its pinch-to-zoom function and its entirely touch-based navigation. The touch input options of Microsoft's Touch Mouse are more limited, but they feel as if they complement the familiar mousing experience, rather than attempt to replace it entirely.
Whether one approach is better than the other is moot, not least because it involves larger questions about operating system preferences (we've never liked the Apple Magic Mouse in general). We expect that most Windows 7 users will find that the Microsoft Touch Mouse speeds navigation in an intuitive manner. Regarding the heavily touch-focused Windows 8, Microsoft would only confirm that we should expect that the Touch Mouse will be compatible. Though $80 seems like a lot to risk now on a device that might not be able to take full advantage of Microsoft's next operating system, the Touch Mouse is effective enough now that we can recommend it for general purposes to any Windows 7 user.