It's easier to have multiple levels of output with an LED light, which is handier than you might think. The flashlights I use the most can run for thirty days continuously on the lowest level. I use "moonlight" mode as a nightlight for my kids in their tent, or for moving around without waking my wife in ours.

Other than overheating (which is easy to avoid if you're not modding your light) anything that breaks the emitter will almost certainly destroy the light. I wouldn't bother carrying an extra emitter, even for C and D-cell MagLEDs which are very easy to replace.

Incans tend to have a warmer tint and therefore render color more accurately.