I've read the previous thread "Grid Loses Selection and Scroll Position On Data Store Load" and tried the way to restore scroll position after ds.load. It works, but "However there is still a visible twitch in the grid as it scrolls to the top and then back to the restored position.", I also tried :
grid = new Ext.grid.Grid('guests', {
            ds: ds,
            cm: colModel,
            view: new Ext.grid.GridView({
                focusRow: Ext.emptyFn,
                ensureVisible: Ext.emptyFn
I think the option to turn off redraw grid while only update data in it is very important requirement. The typical usage such as real time stock quotes display has to have this option, or it can't work well, obviously. So can Ext team put some effort on it?