Actually, as output increases, HIDs easily beat LEDs in runtime. A Polarion Helios PH40 cranks out 4150 lumens for a full hour and 20 minutes in regulation. Show me a portable LED light which can do the same. These superpowerful LEDs need in excess of 9Amps to achieve something even 50% close of that output, but try doing that with a portable battery pack plus a portable cryogenic station in order to keep it cool... Just not happening.
A big +1 to this as I thought this was the best post in the thread so far. (bold emphasis mine)
Even given the unlikely example in OF's post, LED has a better chance of successfully matching the efficiency and output in the future than it ever has of matching the throw performance of HID. While throw performance is related directly to surface brightness, the topic of this thread is "output" which I generically take to mean overall lumens produced. If they can overcome the heat issue, overall lumen output will eventually become possible. On the surface, this obstacle may sound like a simple matter of time and development but it's actually a fairly large gap to overcome. The materials for example aren't going to change than much in the next decade. LED light makers are still stuck with the typical aluminum, copper, brass, ti, SS, ect. The LED dies themselves are also somewhat fixed with the patterns and materials we currently have, so unless new materials are developed that can handle twice the heat in half the space it will remain a barrier. Active or some other means of hyper cooling seems to be the only hope for the near future.
To match the throw of a current 14W HID it would roughly take a die size one half the surface area of the XP-E while producing more than twice the output, resulting in much higher surface brightness. To use OF's phrase, "it's just not happening" now or anytime soon, especially considering the rate of LED advancement we've seen over the last 2 years. They've made advancements but nothing close to what would be required to close the gap. I'm speculating that at some point LED's will undergo some revolution or a completely new technology will emerge.