I generally agree. Luckily now there are much safer Li-ion chemistry options like IMR and LiFePO4. I resisted Li-ions in flashlights for awhile until I bought a Surefire 6P bored for an 18650. Popped in an IMR 18650 and wow, not only is output/runtime greatly increased but I only have 1 battery to worry about. No more having to worry about matching RCR/CR123 batteries.
Interesting- I wonder how to go about doing that with my Surefire Z2? It takes 2 x CR123A cells but one rechargeable would be great if it's compatible with the LED emitter.