There are different technologies used in night vision devices and they have different pros and cons and different use cases. Which one you pick will depend on what you want to do with it.
Image-intensifiers; these take what ambient light there is and boost it. They are great for seeing the world around you, for navigating in the dark, for seeing while not being seen. There are two basic varieties: analogue and digital. The analogue ones have very low latency they can even be used for driving. The downside is cost, the latest ones can be many thousands. Digital ones are much more affordable, the price has come down and capability gone up recently as with small electronic things generally. The main disadvantage with digital ones is the latency, there is a noticeable delay between the world and your view. One advantage of recent digital intensifiers is you can see in (muted) colour, analogue ones are monochrome.
Active Infra-red; these shine an infra-red light that is invisible to you and to the wildlife, but not to other folk with night vision! The big downside is in effect you are using a torch and as with a torch you can only see as far as your torch beam. The bigger the torch the further you can see but it will cost more, be bigger and use more batteries. Active IR is great for seeing what is right in front of you, you are not going to survey a hillside with it. It is also great for using in total darkness, eg inside buildings. Devices will often combine an image-intensifier with an active IR lamp to fill in the when there is less ambient light.
Thermal; these see the heat given off by things. Thermals are great for finding animals in the dark and also during the day if the animal is in the undergrowth. Thermals aren't the best option if you want to navigate around in the dark, the rock you are going to trip over will be the same temperature as the flat path either side.
The device listed in your opening post and the ATN are digital image intensifiers both with built in IR lights.
The DTI1, DT3 and ZH38 are all thermal.
Which technology route you go down depends on what you want to do with it.
Also be wary of looking at videos of night vision stuff in action. The kit used on wildlife documentaries will be $100,000s you will not get views like that. Consumer kit will also be shown in the best possible conditions, this will be the best view you get with it.
