I think it depends on the strategy and the pokemon role on the team.
Like Fiery Dance over Fire Blast for Sp.attack boost on Volcarona. Or even Rock Slide over Stone-edge on terrakion just to avoid the chance of missing. (even though rock slide always fail to OHKO/2HKO, and no crits :[) Fusion Flare over Blue Flare on Reshiram to avoid miss (in sun, it doesn't matter really. both still deal huge damage) Surf over Hydro pump Keldeo, and other similar cases.
Like Fiery Dance over Fire Blast for Sp.attack boost on Volcarona. Or even Rock Slide over Stone-edge on terrakion just to avoid the chance of missing. (even though rock slide always fail to OHKO/2HKO, and no crits :[) Fusion Flare over Blue Flare on Reshiram to avoid miss (in sun, it doesn't matter really. both still deal huge damage) Surf over Hydro pump Keldeo, and other similar cases.