In the case of distributed parsing onXLE event will mark just the moment when data was loaded and the first bunch of data was processed. The moment when all data was processed and rendered can be detected with onDistributedEnd event.

Event doesn't provide any parameters.

          grid.attachEvent("onDistributedEnd", function(){
                    //any custom logic here
          });

This event has sense only if Distributed Parsing mode was used, and it's never called in other cases.