I have made a purchase of dell wireless opticall mouse a month back.
I found the build quality very good and also the mouse is not so heavy as compared to other wireless mouses. The most important thing I like was the range.
I was working on my pc from a distance of approx 4 metre but interesting to see the fact that it was still working. Also the mouse is quite responsive and you can just plug and play the device.
The battery power consumption of the mouse is also upto the mark and is still running well after a month on heavy usage.
All in all the product is good and you can go for it.