The following table lists some of the advantages and disadvantages of these two operations.
| Operation | Advantages | Disadvantages |
|---|---|---|
| MaxWaitSeconds=0 | Returns only properties that have changed since the version specified. Use this to poll for changes without waiting for changes. | Returns an empty set when nothing has changed on the server. Depending on your client application, this might be inefficient. |
| MaxWaitSeconds>0 | Waits until an update occurs or a time-out occurs. Efficient use of network resources. | This can block a thread until updates occur. However, you can cancel this call while waiting, by using CancelWaitForUpdates. |
