Per my understanding, Hidden Power type is effected by STAB and weather boost, i.e. your HP-flying and HP-fire will deal 11 DPS
In PvP, Hidden Power is as good as Mud Slap aside from the added bonus of being unpredictable and possibly having STAB.
Its little worse (sans STAB) than Extrasensory in PvE: 10 DPS and 10 EPS, vs 10.9 and 10.9
Thank you. Much appreciated