as far as i'm aware Chris sent out an unplated Titanium (which means an unplated brass(?) core), which was a "sneak preview" given out before the CE set is released (as a good-will gesture, of sorts). However, im not sure if you receive another with your whole CE set, when it arrives, (someone else could comment on this). Chris, at some point, was also giving out free blue obsessions (or the set, as you mentioned) and sending the blue extremes separate from the CE set so people didn't have to wait as long for a puzzle to solve, (again, i don't know if you receive another with the CE set or not).
again, as far as im aware, if the CE set does indeed come with an Obsession Set, then the Level 1 Blue is the same as the Blue Extreme, and the Green Obsession is the the same as the Green Extreme. However, im uncertain whether you can ask for specific puzzles from the CE set to be disassembled, with the others still being assembled, but you will have to email Joseph (Revoguy) or Chris and ask.
Hope i have helped with my ramblings

and good luck with your puzzles when they arrive
