There are ways in which the optimization techniques described above can affect your usage of the control. For example, if you have code in your application that is walking over the visual tree of elements in one of the 'xam' controls, you should be aware that not all the elements you expect to be present will be there. Specifically, CellValuePresenter elements may be "missing" from the Visual tree if they have not yet been scrolled into view. Similarly, if you are looking for RecordPresenter elements for records that have been scrolled out of view, they too will be missing from the Visual tree. In general, though, the optimizations described above should be transparent to your usage of the controls.