Having used the basic optical MS mouse before I was happy with it. This one is smaller in size (meaning your hand is much bigger than the mouse and falls around it), feels cheap (light plastic which feels empty inside), and the mouse-click noise is much stronger than the old basic MS optical mouse. Before you could not hear the clicking sound so much. Now you can definitely hear it and if you're on the phone the other person can also hear you clearly clicking. All in all, ok, it works..but the build quality is not the same. I like the old version better: it was bigger (easier to hold), quieter and less emppty-plastic-y.