Q5 refers to the LED, in no way do the terms "R2, Q5, R4, R5, Q3-5A" refer to anything but the LED.
The LED's most lights use come from a few manufacturers, namely, Cree (XR/P line), Seoul SemiConductors, Phillips LumiLED's, Osram, etc. These manufacturers produce efficient, varying brightness LED's, for the market. Some produce high output or custom LED's, and some produce other types, such as lower output (250+ lumen) LED's that are extremely efficient, and some excel at producing high CRI (color Rendering Index) LED's.
Jetbeams are regulated, as are most expensive, high-end lights (excepting Coast/LL lights, which are just expensive). Jetbeams lights seem to be very directed to the "thrower" type, although you can purchase OP (orange peel, refers to the texture of the reflector, like the skin of an orange; used to produce wider, cleaner beams of light, but sacrifice some throw) reflectors in some places.
You say you need a light for long distance outdoors illumination... I would suggest looking for a light that offers neutral or warm color temperature LED's. You'll see an appreciable decrease in output, as compared to "cold" white LED's most lights come with standard, but color distinction at long ranges will be easier to distinguish.
You see (here's the short version)...
Humans have adapted to seeing colors on a planet that circles a red star. That's why colors are the best looking under direct sunlight. However, the "white" LED's we use are actually a blue LED, which has a layer of phosphor, which kind of "converts" the blue wavelengths of light, into a white light. However, on a white wall, we are often able to distinguish a bluish tinge to these "cold" white (~6000*kelvin+).
Incandescent lightbulbs are inherently inefficient, because they emit "light" in wavelengths both above and below our receptive ability (infrared and UltraViolet; remember, light is waves of energy which we are able to perceive only a narrow band of).
In contrast, LED's are very efficient, because they only produce "light" in a narrow band. This is good, because we are able to fine tune what kind of wavelengths we want (though with some difficulty), but bad, b/c they don't emit light in all the wavelengths we are able to percieve as light, reducing their ability to render color accurately.
High CRI LED's are produced in such a way(I think), that they produce more red light, enhancing color rendition.
Found a set of 4 batteries + charger on ebay for just $12 (3.7V CR123) - and it just works GREAT.
