Are these remarks from first-hand product knowledge?
As far as the weight, the Bel Canto eVo6 is 6x120 and weighs in at 42 lbs. I am not suggesting that the Pio is anywhere close in class to the eVo, but a good portion of the weight in the Bel Canto is from internal shielding (4 layer chassis). Additonal shielding in the Pio could offset some of the weight savings in the power circuitry and explain the Pio's middle-ground weight. this is consistent with what I heard (and posted) in earlier discussion - that Pioneer had improved audio performance and internal shielding. This is only information that has been passed on to me so I am claiming no "special" knowledge.
Of course, if you have more information on the new design, I am sure there are many here who would love to hear it, especially if it is firsthand.