I use a thermal scope but its not mounted on the rifle i use it as a spotting scope.
I mounted it on my s200 a few years ago it took an age too zero in
but it would pick rabbits heat signiture up out too a 100 yards easly.
If you shoot nice grassy fields its great,if you shoot where there is thistles,fern etc it is a nightmare as you can spot the rabbit but not the undergrowth in front of the target.i think if you shoot a rimfire and upwards (then a thistle wont be a problem) it is a great scope too have.
Another thing is it makes you light blind for a few moments when you move it from your eye which is a pain if your on foot and you need too collect a rabbit quickly.
I will fit it too the rimfire someday im sure.