I've noticed that calling endEdit on a record inside of a grid causes the whole row to be removed and a new row to be inserted (which is a very expensive operation) regardless of the values actually modified. Just updating 5 cells (on 5 different rows) locks 1.7 Ghz Celeron at 100% CPU usage. That's terrible.
My question is: why isn't there a method to just update the value of a cell, without any DOM manipulations (which are completely unnecessary)? Currently I am thinking of doing it myself, as the default ExtJS behavior is amazingly slow.