What is shown below is mostly self-explanatory. See non-trivial notes among simulation comments.
First - two reference lights for comparison.
Philips Saferide 80. A good well-known light. Stock LEDs - Luxeon Rebels.
Generic "MagicShine"-type circular reflector. A bad well-known light. Cree XML (LT50E3).
Lens-based lights. LEDs - Cree XML (LT50E3).
UPD, Nov 2016: "Far" below is from older setup, when it was used as Far light. Now it is used upside-down as High-beam light.
Far widened by the diffuser.
Far and Near.
This LID is obtained from combining the Far and Near LIDs.