After upgrading to .NET 4.6.1, a datagrid using VirtualizingStackPanel started experiencing performance issues.
It seems the stack panel kept looping through all elements of the grid's data source in order to calculate row heights, even though the height of the row's grid is fixed.
It breaks our data virtualization, since all collection elements are accessed, and not only those that are visible at a given time.
Setting IsVirtualizingStackPanel_45Compatible to TRUE in the appSettings restores the performances as they were in 4.5.2, but we do not know what other consequences are.
There seems to be a bug in datagrid virtualization introduced in .NET 4.6.1