A good budget mouse with a few flaws that keep it from greatness.
So far the mouse seems pretty good. It feels very comfortable in my hand, with good button placement with the exception of the back button. The USB receiver is fairly large (sticks out ~5cm from the port), which is forgivable at the sale price, but at the MSRP of $30, you should be able to find ones...
At the current sale price of $9.99, it is fantastic value for money; The tracking is excellent on both mousepad and bare-desktop surfaces, even relative to my desktop MS Wireless Intellimouse Explorer 2.0; Ergonomics are spot-on (other than back button placement) for a laptop mouse.
The back button is placed over 1cm behind the bottom limit of the scroll wheel, making reaching it extremely awkward; I have long fingers and almost have to lift my entire palm off the mouse to curve my finger all the way back to reach it.