The following is just a preference on my part....

I would have preferred if there was a mystic adept option that had been a combination aspected magician/adept rather than magician/adept.

My online group from last fall tried to houserule that in, actually.

But we ended up complicating it way past playable.

That's not a bad idea actually. Smart way to build a MA is to make them specialists with one type of magic anyway. The real question is how to price it.

I was actually toying with the notion of running a game where the various magical qualities could be "upgraded" to represent learning new abilities over time. So you could start as an adept and then pay 10 karma to upgrade to mystic adept, or start as an aspected or geased mage and then slowly buy up to full magician status. Of course, if a full mage wanted to learn adept abilities things could get weird...

Maybe just let them buy the adept quality on top of the magician quality, and use their full magic stat for both? Say that "mystic adept" costs half as much because they're splitting their magic, and haven't learned to project?

Dunno. It needs some work, but there's definitely an idea there...

It is hard to price an aspected mystic adept in a Priority system. They assume that mages and mystic adepts are synonymous; you give up astral perception and projection, and gain the ability to purchase adept powers instead. But an aspected mystic adept would only be giving up astral perception compared to a normal aspected magician. So if you make them too similar in cost, who would want to play a "regular" aspected magician? I didn't like SR4's implementation of aspected magicians at all, but it was easier to handle aspected mystic adepts when the aspected part was taken as a separate negative quality after buying mystic adept as a positive quality.