i'm sorry but the whole 'quarter on a string' example of gyroscopic effect is completely wrong. A disc given force on it's outer edge (grip area) has an equal and exact opposite weight opposing the outer edge opposing the point of force.
in the string example, there is no opposing weight, just a pivot point. a more accurate example would be a string with two quarters, one on each end, with the string supported perfectly in the middle.
think of it this way: a roulette wheel. if you place your hand on the edge and spin it, it goes until gravity and friction defeat the momentum of the force applied. What you are saying is taking only one 'number section' of a roulette wheel and spinning it. Of course a heavier weight on the end of one piece of a roulette wheel will spin longer. when there is equal weight on the opposite side of the disc (not a string, an entire evenly weighted disc) the effect of the weight on the outer edge is different.
is there still a difference? i dunno. I hope so but I think it's a small one. I truly believe the MVP stuff flies better for some people because they WANT it to fly better for them. power of suggestion and all that.