It was never very useful. If you are typing and you need to quickly use the mouse and the nub is nearby it can be sometimes convenient. Over time the nubs can wear down and cause your cursor to drift so they have to be disabled in the BIOS or physically disconnected. I have never known anyone who wanted to get the nub repaired. People adore the nub but I don't know anyone who admires it and uses it for anything past a small convenience you wouldn't notice if it were gone.