XML or GAU?

I've been looking into gauge creation and editing for awhile now.
The million dollar question is....(drumroll please) XML or GAU.
XML seems to be a much more "open" way of creating gauges. GAU seems to be editing current gauges. Which is cool.
For my plane, I really dont need any kind of special gauge. So I could just edit and clean up gauges that I would need. What are the pro's and cons of XML and GAU? How would I edit an existing gauge?
The million dollar question is....(drumroll please) XML or GAU.


For my plane, I really dont need any kind of special gauge. So I could just edit and clean up gauges that I would need. What are the pro's and cons of XML and GAU? How would I edit an existing gauge?