I have some of flashlights. My favourite one is Armytek Predator because of its UI. It's a good example, you are right. Most of all I like variety of modes :)
My EDC is Armytek Predator. It's multifunctional light. Duration is 1h 20min at 670 lumens and 155 hours! at 6 lumens. And effective range is 437 yards. I'm impressed:)
Sure, good customer service! I didn't have any problems with my replacement. It's a pity that this light has such bug. I can't wait my wizard with the new UI.
Usually I use protected batteries in my lights but in my predator I can use unprotected batteries because of built-in battery protection. I think it depends on your light and its electronics.