The most telling line from ExtremeTech's review of the $99.99 Logitech MX Revolution mouse -- which we also got our hands upon recently -- is: "The MX [comes] with a learning curve". The reason for this? An inordinate number of features that results in a mouse that takes some getting used to. Starting with the scroll wheel, Logitech has devised a way of integrating both the ratcheted type of scroll with the free-spin variety: by default, the mouse will switch between the two modes depending on how fast the user is scrolling. Users can tweak the speed at which the mouse will switch into free-spin mode, and yes, there's a ratcheted only option. The next notably new feature is the "document flip", a second scroll wheel located just above the thumb rest that functions as an application switcher if you decide not to change the software settings. Finally, there's a dedicated search button on the top of the mouse that will either, a) start an internet search for a selected word or, if you don't have anything selected, will b) take you to the homepage of your preferred search engine. In practice, the reviewer found the new features to be in need of a little polish: the scroll wheel was a little too eager to switch into free-spin mode (and doesn't double as a middle mouse button), the document flip felt a little redundant, and the one touch search button bugged-out a few times. Underneath all the features is a relatively basic, multi-buttoned cordless laser mouse -- the 800 DPI sensitivity is nothing to write home about -- but the ergonomics and design live up to the high standards we've come to expect from Logitech. The reviewer concludes that the extra features probably aren't necessary, but could in the long term increase user productivity if prospective buyers spend some time customizing the button functions and getting used to the new features. If you think you can do without the new features, you might consider picking up one of Logitech's other no-frills gaming mice, which feature much higher sensitivities and equal, if not lower, prices.