@garyrussell, may be it make sense to ask SpEL guys from Spring Core team to provide more informative exceptions?
E.g. from this configuration:
````xml
<enricher id="enricher">
	<header name="number" expression="new java.util.Date()" type="int"/>
</enricher>
````
I end up with:
```
Caused by: java.lang.IllegalArgumentException: Cannot convert value of type [java.util.Date] to required type [int]: 
PropertyEditor [org.springframework.beans.propertyeditors.CustomNumberEditor] returned inappropriate value of type [java.util.Date]
```
But it would be better to see which **expression** causes the problem.
As far as SpEL is centeral tool in SI and his issues appear only at run time, to see 'expression string' within StackTrace is good point to fix those issues by end-user quicker.
WDYT?