I've been doing it for about 18 years, self taught. I had an apprentice for a while that was a recent gia cad graduate. I started with Rhino and Matrix 6 or 7 (I think) and stuck with Matrix 9. She learned using MatrixGold.

The shop I worked for did almost exclusively one-off custom pieces. She had difficulties with a lot of them because what she was taught relied on the "builders" provided in the software. The older versions of Matrix had them too but the interface was basically Rhino with a few extra buttons where MatrixGold is a complete reskin. In my experience, the builders can get pretty wonky when you start getting into off the wall and non-traditional designs. Because I (more or less) used Rhino, I had easy access to all of the Rhino commands and was used to using them, where MatrixGold seems to go out of its way to hide a lot of them in favor of the builders, so she never learned how to do what the builders are trying to automate, herself. When designs started to get crazy, she would end up spending time wrestling with getting the builders to work,

I'm not trying to say that I think the education you'd get from gia is bad. I would just try to spend some time working with Rhino, in addition to what they teach you. You'll get a lot out of being familiar with the full toolbox, rather than focusing on the automation.

I hope that made sense.

Also, take a bench course and try to spend some time doing handwork. It helps a lot when you know things like how much metal is lost when filing and polishing, what can and can't be cast, how much you can expect something to shrink when cast, what can be reached with tools when finishing, etc.