• Grid with 1 column set as auto
• Add data (> 30 rows)
• Let grid render
• Clear data
• It takes 1-3 seconds for the grid to refresh.

Here is the main offender:
https://github.com/angular-ui/ng-grid/blob/master/src/classes/grid.js#L442

Each time columns are configured or re-configured, the same listener is attached - this means that with each sorting operation, load operation etc. another listener is attached. After a short time there can be hundreds of those listeners invoked for each next operation.