yalskey said:
The only resonable arguments for a twisty I can gather just from reading around here is that they take up a bit less space and they tend to hold up a bit better over the years (mechanically).
In my experience, twisties are NOT more reliable. Over the years, I've experienced more failures with twisties than with clickies.
I've done a lot of caving, and caving subjects lights to brutal conditions that will expose their flaws in short order. I've never been purposely hard on caving lights, because when they crap out they have to be replaced. However, regular caving use just seems to destroy flashlights. (Canoeing, rock climbing, and winter backpacking are also good for real world durability testing of flashlights.)
I've gone through a lot of flashlights during decades of outdoors recreation, but I can recall only a handful of clicky failures. AshFlash: waterproof, rubber-armored 2D light, made in Hong Kong. Eveready Adventure: waterproof, plastic, gasketed 2D. A Mag 2D. But, I had more specimens of each of these lights that never experienced a clicky failure.
OTOH, I can recall many failures of twisty lights: Pelican Sabrelight, Maglight Solitaire, Pelican Mightylite, Maglite MiniMag, Teknalite 2AA, etc., etc.
I prefer twisties for keychain-type lights, because they don't seem to turn themselves on in my pocket, at least not very often. They allow the light to be somewhat shorter. For me, those are their only advantages.
Ergonomically, they are inferior in every respect to click or slide switches. Every on-off operation puts wear on the threads and O-ring. They tend to clog with pocket lint, grit, and mud.
I have a feeling that some people advocating twisties for survival use haven't actually used them under less than ideal conditions. I agree that small twisties are good emergency/backup lights, when packed away in a rucksack pocket or survival kit. An Inova X1 with fresh cell always rides along in my rucksack for emergency use, in a waterproof ziplock bag.