We have made a change regarding the support stance for App Fabric for SharePoint 2013. The following (poorly worded) KB explains that you are now free to install AppFabric patches as they are released publicly. SharePoint CUs/SPs will not contain fixes for App Fabric. Hopefully this helps to resolve some frustration with the stability/finicky-ness of AppFabric. Links to two more recent App Fabric Cumulative Updates are below.