Hi Brian, we're also running Mendix 4.7.2 on premise and never had any issues. We upgraded to java 7 after migrating to a previous version of Mendix 4 and never had any issues like the one stated in your question.
Our app is using hosting and calling webservices extensively and also very large messages and never had timeouts or issues with the webservices. This is not an answer to your questions, but it could help you making a decision.