Sorry, it is sometimes a little difficult with products like these. You never can tell exactly which LED the manufacturer is using unless you have the manufacturing specifications. Even then, the manufacturer might substitute the LED with what he thinks is an equivalent LED, such as a Chinese LED of equivalent brightness instead of a Nichia. Of course we all know that the non-Nichia LED tends to be overstated in brightness, so 8000mcd is really only 6000mcd. Or the viewing angle might be tightened a little to boost mcd rating, such as having 15deg instead of 20deg. (The mcd will be higher, but the total light output may be no better.)
Perhaps you can try comparing the output of the penlight with a known equivalent, such as a bare LED of known mcd rating driven at spec, an Arc-AAA or Photon microlight or something similar? Then post the result here and someone might be able to tell you what LED was used in your comparison light and you will know the approximate output of your penlight. From there, you can make the decision about the upgrade.
