When grid column is hidden template code is still being executed. For large data sets with many hidden columns this makes grid scroll slower than is necessary...
{ id: 'Artist', title: Columns.ARTIST, field: Columns.ARTIST, width: '100px', hidden: true,
	template: function (dataItem) //this gets executed even when column is hidden. 
	{
		return someMethodToDetermineArtrist(dataItem);
	}
}