I've used several Pulsars, Fir (Armasight) and Trijicon. I've had limited experience with some of the ATN products. Thor and the Digi stuff.]
They all work and will do a job. Just really depends on how you plan to hunt. I mostly use mine for hog hunting and after spending a butt load of money going back and forth on different models and manufacturers I came out using a lower cost Pulsar XQ50 Apex. It provides me with the things I want and the things I don't care for at a very low cost for thermal. Remember, if you need ultra high resolution, like face recognition or some other type of ID thermal may not be the ticket and Gen 3 will be your friend.
I had two XP50's and while they are the most robust in features I wanted more magnification. The Flir PTS536 was probably my favorite but the 4x field of view made it difficult hunting under 100 yards for follow up shots. The Trijicons were more complicated to use but provide overall an outstanding view.
The big thing to remember in thermal is resolution and magnification. They go hand in hand. Each time you double the magnification the resolution is dropped in half. In comparing the higher priced XP50 (640x480, 1.6X - zoomed to 4x) to the Flir PTS536 (320x256, 4x) at the Flir's native 4x the Flir resolved better than the Pulsar looking through them side by side. But the Pulsar at 1.6x is pretty dang awesome and good for close range work.
What will be your hunting style? Do you want extra features like video recording, sound recording, battery packs or other features that some have and others don't.
If I had my druthers I would want something in the 2.5x to 3.2x native power with a resolution of 640x480 and a 12 micron core. This would give good field of view and better range. Probably already out there or coming but more than likely out of my price range for as much as I use it.
Personally I would stay away from ATN. Just my opinion as the devices I've used just weren't up to par with the Pulsar, Flir or Trijicon units. You can do your on search on that.