If you would have to choose between C/R14 and 18650 (let's say both top quality), which one would you chose?
I would choose C/R14 ( a little more heavy , but aveable everywhere , cheap , simple charging ) lion must be really good quality with protecting circuit for discharging and overcharging and really don't like moisture problem is that a very few batteries have advertised capacity
And what about choosing between XR-E R2 and XM-L T6?
depends from use and optics :
XR-E R2 more throwing smaller die with less lumens nice result with lens
XM-L T6 much more power bigger die , wider beam , needs wider lens or reflector ( from 45-65mm), 3x higher consumption , need to be cooled efficient
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i use for backup lamp cree XP-G2 ....litle less
for primary SST-90 10A ....much more
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and advice : buy low quality , will buy twice