Singles all the way. I think I get better hook penetration, and a single doesn't seem to give a fish leverage against other hooks. To explain what I mean, I seem to loose fish hooked with trebles when they roll or flop, and I think sometimes the unburied hooks, when pushed against the sides of a fishes mouth will help push the buries one out. My hook to catch ratio with spoons, spinners, and plugs increased dramatically when I changed everything to singles.