I understand the main differences but based on my photography preferences, the 100 cri of an incan is what I need in complete darkness.. (maybe i should just get one of those big halogen bulbs instead)
In other words, if I can get 100 cri from an incan, then there is no logical reason for me to rule it out as my best option, and then substitute it with an LED that (with today's technology) cannot yet yield 100 cri.
On the more technical issues, though:
Considering that I'd use my best and more expensive lights for photography, the runtime/ fragility drawbacks you speak of don't matter that much to me.
Those flashlights are not going to get banged around, dropped, or even used on high for long periods of the time. As I see things now, low cri LED's are for daily use around the house, work, car, for hunting, self defense, or just walking at night. In a nutshell, I'd only use high CRI LED or modded incans for photography purposes only.
Now that you know of my personal tastes and wishes, thank you for listening to my boring drivel.
"You can get hundreds of lumens with the proper driver and heatsinking using normal AA cells. It'll even give you run times measured at an hour plus."
This is good to know. I was wondering what to do about battery power for high CRI LED's. but... I am confused about the Maglite incan mods. For example, it seems obvious to me that I am much better off going with a 2D Mag (as opposed to a AA mini Mag), if what I want to do is create a high powered incan. This way I am not limited to the wimpy AA battery limit, and I can then use larger bulbs and reflectors.