I bought T20C since I am always looking for a lights than can handle snow and in general winter conditions. Well, I have yet not a chance to try out how the switch works at -30 celsicus temperature, but at least I can guess that it did _not_ not solve issues caused by wet snow that falls from the trees and sometimes gets switch to stuck. Sure bad news is that the switch dont work with 2 X UltraFire 18350-cell configuration that othewise gives reasonable runtime and good voltage boost. They are just too tall: cells fit into light, but the switch works badly, modes dont change properly ans sometimes the light is impossible to switch off. Similar lights that I have are Klarus XT10, Maelstrom X7 and Fenix TK21 U2. Fenix is the lumens king, I guess, but Sunwayman feels like a tool that gets work done. I think it will be used a lot during next winter season..