Roots have always had higher power than Gheist.
but for a while, Gheist just had better abilities, which is why people played them more often.
with the latest roots cards, Roots have seen much more play, which has knocked Gheist slightly below the radar, though i still think Gheist have better abilities.
so, for the Moment, Gheist are slightly lower class.
but Roots was the lower class up until a few weeks ago, before the ELO ban switch.