I completely understand that this is kind of an apples to oranges comparison, but I’m hoping that someone who has experience with both thermal optics can share their experience.

I currently own the StingIR 640. It’s my first and only experience with thermal. I feel like it does a pretty good job of fitting my needs, but it’s definitely a compromise. The things I don’t really care for are (in order of significance):

-Screen size. The physical dimensions of the screen seem really small to me. It makes using the StingIR handheld less than ideal. I couldn’t find the dimensions of the screen from a Google search, but I’m not a huge fan. I realize this is probably to help with the clip-on functionality.

-FOV. The FOV isn’t that bad. It’s only slightly worse than the RH25, but it’s significantly more narrow than something like the NOX18. Walking around with this up to my eye isn’t the most pleasant experience from a panning standpoint. This isn’t a deal breaker for me, but worth bringing up.

-Latency/lag. When panning back and forth, I definitely observe some lag. This was surprising to me as it was stated that this has a 50 Hz refresh rate. I looked in the menu to see if there was a way to adjust the refresh rate and maybe mine was set lower for some reason. I don’t understand how anyone could use this helmet mounted. Maybe my eyes are weird or overly sensitive to that though.

On the other hand. I love being able to hold the StingIR in my hand to scan around, and then throw it on the rail of my rifle in clip on mode. It works really well as a clip on, though again, I wish the screen size was bigger.

Finally, let’s get to the Telos. Let’s get the obvious out of the way first. The Telos can’t be rifled mounted. I’m aware. The Telos is a 2.5x base magnification. I’m aware. With that being said, the screen size on the Telos appears to be larger than the StingIR, though I couldn’t find a dimension for screen size for the Telos either. The image quality also just looks better judging from the reviews and footage I’ve seen.

I’m not against having 2.5x magnification either. I thought having a 1x base mag would be ideal, but I do find myself wondering if the heat signature at 80 yards is a dog or coyote (or bobcat, since we’re starting to get more of those in our area). Forget about identifying anything smaller than a horse at ranges over 150-200 yards. Maybe it’s on me for expecting too much out of the StingIR.

So, if I’m never going to helmet mount the StingIR, is the Telos a big enough upgrade in the handheld scanning department to justify giving up the limited clip on capability that the StingIR gives me? For reference, I don’t really hunt, but I live in a rural farm land area that has hundreds of yards of farm fields with the occasional tree line and I like scanning my surroundings while I let my dogs out at night to make sure they don’t get into any confrontation with the wildlife. The clipon capability was always a “what-if I wanted to take a shot, it would be nice to have” function, and using white light and my day optic would probably be just as useful to scare off any predators.

The screen sizes aren't measured in dimensions, but pixels.  Both are 1024x768.

FOV on the XP50 will be smaller.

I notice a touch of lag with the XP50 as well when moving quickly.

I can tell a coyote from a horse at 400 yards with the XP50.

Never owned or looked through the AGM though.

My only gripes about the XP50 is that it is heavy if you plan to use it for long periods of time and the eye piece sucks.  It is made to help block out light and can be folded out of the way, but it is always in the way and can't be removed without leaving a hard piece of plastic exposed.

I definitely meant the physical size of the screen. I know that both screens have a RESOLUTION of 1024x768.

I got the Telos XP50 last month and my only previous thermal was a COTI on my PVS-14.

It's awesome, really awesome. I am very glad I waited until I could afford a 640 unit.

I need to post a full review in this forum since I have a lot of photos and impressions, but I think for your use case it would be a great buy.

The 2.5x base mag means you can't really focus on anything closer than 15 yards, but the identification quality at distance is amazing. The high resolution makes longer range identification pretty easy, I can tell bunny ears from whitetail ears poking out behind at a log pretty trivially because of the resolution.

I have a COTI for IR laser work/close range stuff but I also have a dedicated NV scope with a mildot reticle. The laser rangefinder on the Telos pairs with this really, really nicely.

Best thing about the Telos is that I end up using it a lot even outside a hunting or shooting context. It stays near the door and I'll usually pop it on for 5 minutes after dark just to see who is out and eating from the compost pile. My whole family likes reviewing the photos and videos it takes and the app it comes with is really, really good.

Actually let me double down on this - the fact that the Telos is wifi enabled and that you can livestream the view to a nearby smart device is amazing. From wildlife watching to hunting to tactical whatever, that's actually a huge bonus.