Summary: if you have some repetitive stress issues, and have smaller hands, and use a claw grip instead of a palm-on grip, this may be your ticket. For me, it's worth the premium price for such a simple mouse. My hands thank me after a long day on the computer, but ymmv.
Pros: small, but not tiny, light...and no retractable cord. I use a claw grip (grab w/ fingertips, not palming the mouse), and have small-ish hands. A larger, heavier mouse really strains my tendons after a long session, this does not.
Cons: bit bit loud on the clicks, and expensive. Oh, and rather basic.
Summary: I like this product. I plugged it into a USB socket on my Lenovo IdeaPad (Windows 7), and the driver loaded automatically. The settings appear in 'control panel - mouse'. It works very well: PnP; buttons are positive; wheel is gently illuminated; small enough for travel, but big enough to use...
Summary: This mouse works great, does exactly what it is supposed to, is precise. I like small details such as the light turning red when on, to match the Thinkpad red details on laptop. The cable does not wind away into the mouse, as my Asus travel mouse did, when travelling.
Excerpt: Last year I became the proud owner of a lovely blue Sony Vaio laptop which I use all the time. It has a very responsive touch pad but sometimes I find it hard work if I am playing a game or doing surveys that require a lot of scrolling and clicking.