the only things I saw change on trying the 4.0 version were the Cell.Row.Font and iGSortType.ByCustomer were no longer available
Read the comprehensive What's New document supplied with the control to find the answers to questions like this. Here are the corresponding excerpts:
7. [New][Change][Improved] In previous versions, you accessed the cell style properties defined for a particular row through a set of properties in the iGRow class – such as CellType, BackColor, CellSelectable, Font, etc. There were no strong naming system used for those properties because of step-by-step development of iGrid in different versions, so it was hard to say whether a property of the iGRow class is related to its cells or defines the look or behavior of the whole row (for instance, like the Type property).
In this version all cell properties nested directly into the iGRow class were removed, and now they should be accessed only through the CellStyle object property. Thus previous calls like
iGrid1.Rows[5].TextAlign = iGContentAlignment.BottomRight;
should be transformed into the following one:
iGrid1.Rows[5].CellStyle.TextAlign = iGContentAlignment.BottomRight;
To minimize memory consumption and time of rows creation, these CellStyle objects (instances of the iGCellStyle class) are null references by default, but they are created on the fly when you access them. This is done for the convenience of coding - to avoid manual creation of iGCellStyle objects in code each time when you change a cell property in a row. This works similar to the iGrid cells, when the cell style object associated with a cell is created automatically when you change a property of the cell.
There is only one drawback in this approach: in this scenario you cannot test whether a row’s CellStyle object is a null reference (i.e. it was not assigned). To allow this, iGrid has the new Boolean CreateRowCellStyleDynamically property which determines whether a row’s CellStyle is created automatically if needed. By default it’s True, and this corresponds to the behavior described above. To prohibit automatic creation of the CellStyle objects in the iGRow instances, set this property to False.
12. [Renaming] The items of the iGSortType enumeration were reordered to have a more logical order when similar items are grouped next to each other. The iGSortType.ByCustomer item was renamed to a more proper name iGSortType.Custom.