Bling, I own an Armasight Apollo 640 clip-on and also a Pulsar XQ38 and although the Apollo is kinda dated imo, there are pro/cons and is comparable. Is it comparable in image for my use (sort of)(& coyote hunting 100-200 yds max)... my clip-on (& I would assume others) are much less flexible in options than the dedicated thermal. Ex- zooming, etc...while my clip-on can zoom and have other functions, in front of a 3x scope, I cannot see my menu very well (b/c it's zoomed 3x from my day-scope), so functionally I never zoom my clip-on and if I did, would not be as good of an image as if I zoomed in my Pulsar. The clip-on is nice to transfer to one gun to another, but when I do that, I still have to re-zero (to collimate the clip-on...or "re-align it" to the day-scope). So saying all that, if I had to choose one, I'd go with a dedicated thermal on a dedicated gun...but having both is nice...even though both are becoming dated. Hope that helps...from a novice night hunter.