I've been using this model of mouse for several years now - I'm on my second of these mice and I thought I'd write a review about it whilst I purchased a different one.
Basically the mouse is comfortable to use and ergonomically very good. The weight is fine and it's good that it's an ambidextrous design - you can use it either left or right handed. The response from the scroll wheel is good with a slight bumpy feeling as you scroll. The build quality is good but could seem a bit plasticky depending on your tastes. It works well on a number of surfaces ranging from the arm of the sofa to a desk. This is a 3 button mouse so pretty basic usage ie no extra buttons to configure for browsing back and forth, open link in new browser window, etc.
I have numerous mice including MS & Logitech cordless mice (both which cost a small fortune in batteries if used a lot) and a
101429: Logitech MX Air Rechargeable Cordless Air Mouse USB (931633-0120) - excellent for a PC connected to a TV (rechargable via cradle). This is the one I choose to use day-in, day-out though for general use. If your a serious gamer, consider an alternative such as
Microsoft Intellimouse Explorer 3.0 which has a greater DPI accuracy.
The only gripe I have is that the left button has gone faulty - this happened to my last one as well (hence me buying a second), but I wouldn't use this to judge the build quality of the mouse as I have used it 8+ hours a day for over 18 months and it's been bashed around when chucked in my laptop bag. The USB connector must be good quality as I unplug it regularly from my docking station into my laptop and vice versa.
At the end of the day a mouse is all about personal preference. Try to pick one that suits you and feels comfortable. Test some out first if possible (go down the local electronics shop, try the mice on the store demo PCs, then come back and order it cheaper on amazon!) If you purchase any Microsoft mouse, install the Intellipoint software from the included CD and change the pointer movement speed and button click speed settings to suit your use.