Some of us use custom cell editors with multiple checkboxes (or other multiple inputs) and right now we can't use the data-bind syntax to automatically update the model when the user moves away from the cell. We also can't use the grid's "save" event because it won't fire.
Please add support for the grid column to bind to arrays, OR at least let us specify in the model or grid declaration that we want the "save" event to fire (even when you wouldn't normally do it).  This event would allow us to manually get the values of all checkboxes and update the model.