Recon Messaging vs. PO Cost Messaging

For 2007, what is the recommended best practice for healthcare to use when it comes to invoice matching? I have a client that is struggling with Recon Messaging and definitely wants to find a better solution around Recon Messaging. I want to help them with this process but I am not sure myself what is the best answer. What is considered healthcares best practices when it comes to Invoice Matching for Recon Messaging vs. PO Cost Messaging? They have the expediter, which is on the buyer side resolving buyer messages, but this process is not helping the buyer group. They are by passing the Recon Queue to resolve the buyer messages. First, can you please tell me what is considered best practice for healthcare? Second, Can you please provide detail support to back your recommendation? Third, is there any reason where the client could not use both Recon and PO Cost Messaging? Fourth, they are currently using Recon Messaging and want to switch to PO Cost Messaging and after they have added another entity, they would like the option to switch back to Recon Messaging. Any profound desires to express your self is definitely Appreciated.