This should not be a shocker to anyone, but the amount of toolbar that is visible on a users machine varies greatly with screen resolution. Best case scenario, the users that you have in mind all use a computer just like your development machine, and all have the great sense to set their resolution just like yours, then of course you would be guaranteed that they would see every single toolbar item just as you meticulously laid them out. Worst case scenario, well, you could get lucky and they call the help desk asking where that button disappeared to, or maybe they just walk to the competing product, you will never know. Fortunately one simple setting will put your invisible toolbar items in a dropdown menu to the right of the visible toolbar items. The extjs example can be found here (http://docs.sencha.com/ext-js/4-1/#!/example/toolbar/overflow.html).

The code that makes this possible is:

layout: {
      overflowHandler: 'Menu'
}