RonKyle (3/11/2012)
The article should have mentioned that this is very useful for external data sources that would otherwise cause the user to have to wait for several minutes while all the data is validated. Without this, I haven't found a reason for turning the feature on.
As Koen says, to support expressions which are valid only at run-time. In addition, setting the property to true will halve the time it takes to validate the component at run-time thereby reducing its overall execution time.