Claim check example - why use persistent storage

[Jim Talbut]

Hi,

In the claim check example (http://camel.apache.org/claim-check.html) 
the 'unwanted' information is placed in persistent storage and a tag is 
added to the exchange.
What are the merits of doing this as opposed to simply storing the 
information in the exchange?
i.e.:
exchange.setProperty( ORIGINAL_BODY, body);



The only benefit I can think of is that the storing just a tag for the 
data is more secure (there is no way for the intermediate processors to 
access it), but are there any other benefits?

Thanks

Jim