Geeze, i got my logitech optical mouse some time ago when my old mouse bit the dust and let me tell you, the difference between optical and ball mouse is phenominally diffrent. At work we still have ball mice and the move like mud compared to what I have at home. Also, ball mice seem more prone to breaking. When I was in school we couldnt keep those things in work order for nothin! I can't imagine going back !*shudders*