Reviewed by Dante D'Orazio (Currently owns)
I'm probably going to have to say a lot here to convince most of you that a mouse with a $99.99 MSRP (you can find it for $70 nowadays) is worth buying. Sure, the gamers among us know that what you spend on your mouse is going to pay off, but honestly, it's not just gamers that need to demand performance out of a tool that you're going to use all day.
I know some people have been intimidated by this mouse — it's big and, unlike most mice, it's not ambidextrous. After you start using the Performance MX you'll see everything about it is designed to make it a natural tool for helping you interface with your computer. Even after a full day of use my hands never hurt, and there're just enough buttons here to help you get what you need done without getting in your way. In addition to left, right, and middle-click buttons, there are customizable up and down buttons on the left edge, under which a "zoom" button is hidden. Lastly, there's a button integrated into the rubber thumb rest that by default performs a mission control-esque function on PCs with Logitech's (sub-par) Setpoint software.
As my co-worker William says in his review, scrolling behavior in OS X is not what it should be, though the third-party Steermouse app does let you customize things a bit and hopefully you'll be able to hone in the speed and acceleration you're looking for.
Lastly, something that's pretty easy to gloss over when you're looking into this mouse is that it's charged over the now-ubiquitous micro USB connector, which means you'll be able to keep on using the mouse after its user-replaceable rechargeable battery dies.
tl;dr: Unless you're a gamer with really specific needs, buy this mouse! It's fantastic.