Using an indexer to retrieve grid[row, col].CellValue triggers events (like QueryCellInfo). If this is a GridControl where the data is stored in the grid, you can avoid triggerring these events (which slow things down) by accessing the GridData directly.
GridStyleInfo style;
GridStyleInfoStore store = grid.Data[rowIndex, colIndex];
if (store != null)
style = new GridStyleInfo(store);
else
style = new GridStyleInfo();
object cellValue = style.CellValue;