OK, maybe it's reason 527, I lost count.
However, as I detail here, Model-Glue makes it very easy to move functionality around from page to page within an application by merely moving or copying blocks of XML inside your model-glue.xml file.
Here's the 10 second summary of what happened. Yesterday we had a requirements change in an application. There was a piece of HTML code which appeared on one page that needed to be removed and placed in another page. There was some logic in the application which determined if the HTML code should appear, and this logic did not change. Since this logic did not change, all I needed to do was move a <message> block and an <include> block from one <event-handler> to another and reinitialize the application.
I know this kind of change can be done easily in any well-architected application, but to move functionality around with writing or altering 1 line of ColdFusion code is pretty sweet. Now imagine if it was more than just some simple HTML. Imagine if you needed to move an entire form from one page and include it in another. Assuming there were no business rules changes to go along with this, you would simply need to change your model-glue.xml file and it will just work.
Check out the full post for more details