Currently, my primary light is a Nitecore E4K with a Nitecore Tip 2 as a backup. If I have to choose between Fenix and Surefire, Fenix would be the primary as it tends to have more usable settings and is less expensive to replace. If there's a blackout, and I'm the only one around with a flashlight, I'd rather be holding the cheaper light run on low to limit attacks to steal it. I also tend to prefer to save my best and most reliable gear for emergencies so the Surefire would be kept in reserve. I really hate seeing a lot of the cheap, unreliable garbage that is pedalled as emergency gear. If it's your emergency or backup gear, it needs to be just as reliable as your primary gear. Never bother carrying something for survival that is only reliable as a paperweight.