First things first, Don't trust the runtime. Yes, the light will be on after 50 hours but the output won't be helpful.
Second of all, output won't be much(actually helpful if you often go on night hikes and times when you don't want to disturb anyone, but most good lights also have a low mode for that) and they probably over driver their 5mm LEDs which drastically shorter their life(not much heatsinking in those plastic 5mm LED packages, a single under driver high power LED can out lumen those any day).
And lastly, they probably are a bit overpriced.
But that depends on how you determine "useful".