Devil's Advocate here... :naughty:
OK, I know we all like to use "free" power (rechargeables) for our lights, and I do too. BUT...
Most, if not all, of us like to keep a stash of CR123's for use as backup power for when the house power goes down and we can't recharge.
My personal stash size is generally kept around 50 to 60 of the CR123's.
The thing is, these stash batteries need to be rotated so that we always have fresh stock (despite of the claim of 10 years shelf life).
So while I often use 18650 rechargeables in my two-cell lights, I always use CR123's in all my single cell lights for the purpose of slowly and gradually using up my stash so that it can be restocked once in a while.
I rotate the use of my single cell CR123 lights (E1L, L1, E1B), but I use them often. Even then, I might have to replace one cell in the three about every six weeks.
So anyway, instead of messing with RCR123's and their lesser runtimes compared to primary CR123's, why not use your single cell lights as an excuse to "rotate your stock"?
Just giving another perspective...
