I've had one of those old 2-button mice for a long time, an unbranded device with no central scroll wheel that tended to get dirty and stuck very often so that you lost any accuracy on the screen pointer. You had to tear the thing apart, clean the ball and put it back in that became very annoying after a while.
I've had several problems trying optical mice due to the reflecting surface of my desk and a ball mouse was mandatory requirement for me so I decided to go buy and Samsun Pleomax SW 700. First of all over the time I've tended to lean more and more towards branded products because in my experience they've given me far fewer problems than unbranded ones and so far this mouse is no exception.
The color of the plastic this device is made of is graphite black, the grip on the Pleomax feels solid and it's not too light that greatly helps the whole experience with it. You get a scroll wheel that eases the navigation of tall pages including websites and large pdf documents. The mouse is NOT wireless since I've had problems with the accuracy of them too and didn't want to repeat the mistake.
I didn't need to install anything and my older pc recognized it automatically. I believe you get additional features if you install the CD it comes with, but honestly I didn't need it at all. In essence, I could find no downsides so far and I recommend it to anybody that needs a simple mouse that JUST WORKS!