The scene: A level 10 College of Swords Bard (includes extra attack). Crossbow Expert. Sharpshooter. 20 Dexterity. Hand crossbow + 1.
Intelligence is his dump stat so he needs to ask a friend what to pick for his magical secret.
One is definitely Find Greater Steed, because he is going to ride on a griffon while raining down death with his hand crossbow. The other may or may not be Swift Quiver.
Greater Invisibility will give me 2 attacks with my action, 1 attack as a bonus action, +10 to hit with advantage.
Swift Quiver will give me 2 attacks with my action, 2 attacks with my bonus action, +10 to hit.
Ignoring opportunity costs, spell slots costs, defence and anything else other than crossbow damage per round, at what point is it better to use Swift Quiver vs Greater Invisibility?