Little background--My dad has a Surefire E2E that he received last year.  He also does a lot of hunting (deer) and is red color blind.  As we all know the surefire lights are the bomb, but 90min run times w/ the standard bulb are going to get $$ using them for hunting.

Has anyone ever used the 25 lumen replacement lamp that has 2-hr run time *and/or* the blue filter that is supposed to improve traces of blood visually? Would this be a good way to go OR
Is the led head assembly a better alternative?

My primary concern is that he use the light for hunting and that a good run-time is achieved.  The blue filter, if it works, is an added plus.

thanks