LED efficiency

Short and simple: XM-L on stars arent that expensive and compared to XR-E at the same current put out more light + less heat.

Is the difference worth modding?

The bigger difference (assuming you aren’t changing the driver in your example) would be the beam profile.

Yeah, would be a floody flashlight. Driver would be around 800-1000mA. But if that wouldnt be much of a difference, I wont do it.^^

It would be more efficient but given the way our eyes perceive increases in output it wouldn’t be a major difference other than the beam profile.

Alright, thank you very much. :)

I didnt have anything special in mind, I just thought about modding one of those <10$ zoomie flashlights from ebay just to try it. But if theres not much of an improvement, I think I'll discard that idea.

Maybe a UF-H3 with an XP-G or XM-L could be fancy..^^

Thanks for the comparison, I might end up modding something just for fun eventually. :D

With XR-E optics you mean the aspheric lenses? I've read that they dont really work with XM-Ls as they are rather floody.. so I might have to change the distance between emitter and lense when swapping an XR-E for an XP-G to achieve satisfying results?