It would be nice to have a "Preview" check-box option, like in Photoshop, within the Symbol Editor. With it checked, you could see the changes take place on your map while you are adjusting, rather than having to click "OK" (for all the sub-levels you might be into) to see the effect. (That most times needs another small tweak requiring you to drill-down back to that sub-level where the adjusting was happening.)
