As to the lume, personally I've not found the lume on most watches to be all that useful. Most lume used today is "charged" by exposure to light. How long the exposure is, and how bright the light exposed to, will affect both the brightness of the lume and its duration.
If one needs a watch he can reliably and clearly read in the dark, he'd probably be best served with a watch, as available from several makers, with tritium illumination.
Tritium is a radioactive isotope of hydrogen. A small amount gets sealed in small glass vials coasted on the inside with a phosphorescent substance that glows when excited by the products of the radioactive decay of the tritium. For a watch application, these very small vials can be affixed to the dial and the hands causing them to glow quite brightly in the dark.
I have such a watch for those rare occasions in which being able to tell time in the dark is particularly important to me.