Continuing from the discussion here:
WPF inbox views (DataGrid, ListView, TableView, etc) use VirtualzingStackPanel which supports both item mode and pixel mode with virtualized data. Item mode is equivalent to what Xceed's DataGrid does today (per item scrolling).
At best, it's jerky and unpleasant scrolling. At worst it causes data loss as if you have a row that's partially off screen you may be unable to read the rest of the row's data when you scroll to the next item because it pushes the previous item off screen.
The Xceed DataGrid's TableView should support virtualized pixel mode scrolling just like the inbox WPF DataGrid does through VirtualizingStackPanel.