Orbs "Do NOT stack" means grabbing two of the same orb gives you no bonus and robs a teammate the opportunity to grab an orb. Don't do this.

According to Physiologic, if you are using an elixir and grab an orb, the orb overrides the elixir until the orb wears off. They do NOT stack with elixirs. If you are on a ×2 or higher elixir, don't grab the orb. I have a message about this in one of my quick chat slots since it's not generally known.

Grabbing a Gurgox orb right at the beginning of battle is also useless. You need to wait for Gurgox to begin his scream.