The point is that data sent in a SOAP body has to be:
1. encoded into XML - time consuming
2. transmitted - XML much bulkier than original data
3. parsed from XML to some data structure - time consuming
So far we are missing the client side - what is requsting this data?
If you want to move
Java objects from server to Java on the client, it would be fast to serialize the whole collection of objects as a response to a REST style GET. You will find that a lot faster than anything involving XML - one reason being that there will be no concerns about UNICODE character reading.
If you have not studied Java serialization of Objects, its time to learn.
Bill