Thats interesting. it looks like the less expensive XQ38 has a slightly higher resolution but larger pixels (384x 288 17um pixels) than the more expensive XM50 at 320x240 and 12 um pixels. I guess the smaller pixels did not make up for the loss of resolution.The zoom resolution is true to all thermals, because it is digital zoom (like your cell phone), not optical zoom (like your rifle scope) . So all that they do when you zoom in is blow up the original image, which gets grainy.
So resolution and microns are the more important specs of a thermal to look at. Lower microns are better (I think), higher resolution is better. The XP50 has double the resolution of my XQ38, so the XP50 zoomed in to 4x will have the same picture clarity as my XQ38 on 2x base. But with that said, my XQ38 is good enough for me to be able to identify hogs vs deer at 600 yards or so. The XP50 makes it easier, but I dont want to pay that much more for it. I dont know how they compare to something like the XM30, but I would want to talk to someone who has experience with them all before buying one. A friend has the XM50, which is more expensive than my XQ38, but my XQ38 has a better picture. I've seen some thermals that were high end several years ago, and everything just looks like a blob unless you are inside of 100 yards. You'd hate to spend $2200 on a scope and be disappointed with it, when you could have spent $1000 more for something you'd be really happy with.