I needed this control and I found that is quite complicated than other controls.

Data binding reqiures to implement hierarhy enumeration what is difficult to do.
On client side you must implement cascade checking by you self.
There is no tree filter in grid panels header.

Overall a way above other controls standard.

A long time ago I used Telerik tree view and that is superbly experience. It binds to any datasouce, just set what is ID column and what is ParentID column and control do the rest by itself. Checkboxes are automatically cascade if you want (there is option for that), and you can put treeview control in grid header to filter data.

So that is my suggestion: make this great control simpler and better.