No experience with that one, but for the price, I can’t imagine it’s very good.
I have an IR Patrol and with 640×480 resolution, 12x digital zoom, and 30hz frame rate, I can tell the difference between a cow and hog, or spot something as small as a rabbit in a mowed field at 300yds or so when the air temp is 50degF or less. In rocky terrain, warmer weather, high humidity, or lots of brush etc, distance for target ID is greatly reduced.
When they say “detection” at 750 yds, I’m guessing that means you’d see a warm smudge in a mowed field when the weather is cool and dry. With 320×240 resolution, that would mean half the performance of the IR Patrol… AT BEST.
Thermal imaging is pretty awesome, but you’re going to get what you pay for.