Well, I've been comparing the Olight M22 to the ArmyTek Viking.
Winner is the Viking.
The Olight has a few features I don't like. The cigar ring is slip on, not screw on. The pocket clip must be attached to the cigar ring to mount it. This means that you cannot have the cigar ring without the pocket clip and you cannot have the pocket clip without the cigar ring. When you remove the cigar ring there is no replacement ring to take up the space, so you end up with a gap, and a couple of sharp cut-outs where the pocket clip would locate.
The second O ring is forward of the tail cap and the tail cap does not ride over it when screwed fully forward. So what is the point ?
The Olight feels flimsy compared to the ArmyTek. Light output is about the same, but the Olight drops from 950 lumens to 600 lumens after a few minutes. The ArmyTek may do this too, but the manual does not say, and I've not noticed it in use.
The Olight has a spring on the positive (front) terminal, the ArmyTek does not. At first I thought that this was a major disadvantage (for rifle mounting) but then I looked in a Streamlight TLR-1 and found that it does not have springs at the front terminals – so perhaps they are not needed - I've not heard of TLR-1 failures.
If you can have only one, get the ArmyTek
