By all implications, MSSJ Gohan was slightly > MSSJ Goku during the Cell Games. Therefore, SSJ2 Gohan should be slightly > MSSJ Goku + KaioKen. And like some have said: Goku can only sustain the KK for a very short duration of time, whereas SSJ2 Gohan can sustain that level for an extended period of time.
So yeah, Gohan stomps.