Let me state something that I say fairly often - at the end of the day the only thing that should matter is how the world looks to you at night using the night vision goggles you like no matter what the specification sheet states, or who makes them. Some folks will go for low EBI for example, and completely ignore the fact that that the goggle with that fantastic low EBI number they tout may also have (for example) a very low signal to noise ratio. Low EBI versus high SNR, which one? I'd probably go with the higher SNR, but even if I did, how the world looks through those goggles still trumps the numbers on the spec sheet, because everyone's brains interpret images differently. It's one reason there are so many rifle scopes on the market - why not just buy the one with the best specs? Because, it's more than just the number(s). The method of construction of a tube is pretty much the same for all the manufacturers, except for our Ultimate tube which is radically different. The critical elements and what makes our tubes different from the others is the type of coatings we use, the construction of the microchannel plate, the photocathode, and the front and rear objectives. A lot of folks will build their own NODS and don't give much thought to the fact that the whole is greater than the sum of its parts. All of the parts have to be made to work with each other - not just from a mechanical perspective, but from a scientific integration perspective. L3 NODS work best with L3 image intensifier tubes, for example, and Photonis Defense NODS work best with Photonis image intensifier tubes.