Not quite the answer I was looking for - but thanks.
I'm looking more for if there are supposed to be more characters with one than the other and if so, how do I find them.
All of this was prompted by an email I got which had an interview with someone who was saying
Without access to an OpenType feature or glyphs panel, youíre restricted by decisions I made concerning the standard character set and how itís intended to function. With OT access, you can override my choices. (MyFonts June 2012 Newsletter)
But I have no real clue as to how to do any of that, or why they are even there, and if I have access to those things or not - and if I do, how do I access them?