For whatever it's worth, I picked up one of those Skullboy Theories from Community, too, and don't really notice a difference from stock Neutron. The core is maybe on the stiff side, but I have stock discs that feel the same in hand. Of course, it's 75 in New Orleans right now; maybe the difference stands out in colder temps.
Haven't spent much time with the Theory yet, but from the work I've gotten in with it I've been pretty shocked at how controllable its understability is. I've had it fade out on a number of shots because I overestimated how much it would turn. This is a good thing - it seems quite reliable relative to its stability.
The other thing that I noticed was that it felt a bit faster than the Tangent. I know it's the same core, but the Theory is shallower, so perhaps that accounts for it? It just seems to have more speed than I expected it too.
Very intrigued by this disc. I think it could give the Tangents a run for their money. Comparing the two, the Tangents seem to have more lateral motion than the Theory - maybe that's because the Theory has less fade but not a ton more turn, so it's been easier for me to throw it dead straight. It reminds me of a slower Inspire, which is another disc that I still expect to be less stable than it is at times. This is a great addition to the MVP/Axiom lineup for sure.