Going through the modes should be foolproof. Push the tailcap button. You can use half presses to change the settings, push the button in all the way twice within a couple seconds, or turn the tailcap while the light is on (to off) and twist the tailcap back and forth to change settings. You can turn it on in high or low (by turning the head) and use the switch as a clicky, a twisty, or a combination of the two. With a textured reflector, the L2D won't have as bright of a hotspot as a light with a smooth reflector. That's probably why it doesn't seem as bright as the Dorcy. Use it at night and you'll notice some difference in brightness overall. You got a great light. Nice choice. Now you should consider getting the L1D and P2D bodies so you can choose the best size, brightness, and battery type for each situation you use it in.