I think that the Frenzy version is better against black-based midrange decks and ground-based creature decks, so I would say it is better against Rakdos Midrange, Mono White Humans and Rakdos Sacrifice
At the beginning of each upkeep, it returns up to two creatures with power 2 or less from your graveyard directly to the battlefield, then enhances them with +1/+1 counters
Granting them vigilance and unblockable is pretty good in these decks, so Pym Particles has a home
As noted above, prices are expected to be a bit volatile for the first couple weeks following launch
Navigating the array of Pokmon TCG products is an adventure in itself
Both decks lean toward an Aggro playstyle, packing in 26 Creatures each (many of which are double-sided, using Innistrad's Day/Night switching mechanic)