I have had this light for about 2 years , and have found it to be an excellent light for the price. It works wonderfully off of primary cells (CR123), but is somewhat touchy when it comes to 18650s you have to make sure you get the right ones. I can also verify that the button top cells from orbtronic work well. I'm sure there are several other brands that will work fine, but I tried at least one brand that would not contact the terminal on the inside of the flashlight because the tip of the battery would not reach down far enough. Just stay with a brand that tightly follows spec. All that aside, the things I do like about this light a lot are: 1: The belt clip is great for deep pocket carry though I wish that the small part of the clip were about an inch longer to get a better grip on your pocket when the flashlight is being carried tip down, and the pocket is not quite deep enough. That is not a problem if you're OK carrying the flashlight tip up. 2: Two years later, I still feel the output of the flashlight is spectacular for a light of this size, having a slightly larger head then many lights in this class it has a much better more focused throw then some other lights with the same lumen output. I'm sure other lights are out there that are brighter, but this is right at that place where it's "bright enough" and if you make it brighter it eats batteries and just kills people's eyes. 3. Burn time has proven to be so much better than I initially expected from a light this bright and powerful. I've used it with the afformentioned orbtronic 3400mah 18650's and gotten through entire evenings of standing in the rain doing service work on only a couple of batteries for 4-5 hours of mostly continuous with some intermittent run time. I generally carry (4) 18650's when I go out on a night call and I've never used more than 2 and just starting into the 3rd when we wrapped up the call (which was 5 hours) Buy a good multi bank charger, because these larger cells charge slowly if you drain them all the way. It's better for them if you stop half way ( soon as it starts to dim) and swap to another battery than to burn that one to the ground. So buy around 8 cells and rotate them through the charger. Get yourself a StoreACell for 18650's for the other 4 to keep on you in a bag. 4: This flashlight also has the right modes, especially for a tactical light or a work light. I prefer run mine on the mode which gives you high first/then strobe/then low, but as a work light it can also be set on High Only. The great thing about it is, you don't have to cycle all the way through in order to get back around. If you turn it on high, and turn it back off that's all you'll ever see you don't have to click through all the modes. If you turn it on high and double bump it you'll get strobe, but if you turn it off you'll never see the logo mode, because when you turn it back on again it starts over at high. That's what I want in a tactical light, I wouldn't even care if this light didn't even have a low on it. It does have two other modes, if you prefer A different selection or order of the settings. 5: Durability: having now owned this for almost 2 years and carried it literally every day in pocket...this is a tough light. Mine has dings, scratches, road rash, most of the anodizing is wearing off (which means I'm rubbing the outer layer of aluminum off the barrel in my pocket)... but the light is as bright as when I bought it, the switch still works perfectly (which is where all my other lights normally fail) and I could not be happier with the small exception of just wishing for a slightly modified pocket clip design. Compared to other brands I've owned that were this durable and pleasant to use with features anywhere close... I could buy two possibly three lights like these for the price of the brand I was using before, and those did not use recharging batteries, only CR123...so cost was killing me. Best compliment I can give to any tool... If I lost it today, tomorrow I'd go buy another one...