I may be wrong (I've only listened to a few of the tracks), but I think the advanced pack is just the song broken up into more parts so that you can really experiment with it.
I may be wrong (I've only listened to a few of the tracks), but I think the advanced pack is just the song broken up into more parts so that you can really experiment with it.
On the Wing and Strings+Attractors also have an "extras" folder of extra stuff. I didn't take more than a cursory look at them, but they're not just extra multitrack components; their lengths are different from the rest of the tracks, and can't be just played on top of the main components. So yeah, it's extra stuff of one sort or another.
They seem to be demo/idea tracks which are pretty neat to listen to. Example: "TR_Idea 2.01_02" in the Strings and Attractors extras is an 18 minute file that's basically Trent messing around with an idea before it resulted in the "Pitch Machine 1 Stem" track. It has lots and lots of variations of that stem; people can easily cut portions of it and utilize it for remix means.