I can say from experience that Stunball is probably the best combat spell in the game. Low Drain, resisted only by Willpower, Area Effect, non-lethal, Mana spell. Works against any living target, in the meat or in astral. Doesn't make a mess, so you need not hesitate to use it in situations where killing would be detrimental. If cast at a decent Force (which you can do because the Drain is low), it has a good chance of knocking out most adversaries. One quick cast and boom, the targets are out cold for the better part of an hour. The only thing it isn't good against is drones and vehicles and other non-living objects.
By contrast, Orgy would only inconvenience the enemy temporary. Once you got out of sight and could no longer sustain it, they would recover entirely and probably be pissed off. After all, you essentially just violated them.