I admire IRD products. That company seems to have done a pretty good job with thermal monoculars and sights, but given all that, they are pricey. I really enjoy coyote hunting and probably spend more money doing that than I should. Even so, I could not bring myself to spend the price of IRD equipment when I could buy an Apex that did the job quite well. The higher resolution is nice and fun to use, but for me, it doesn't find and kill the coyotes any better than my good ole Apex 50A. I would also offer that my needs are served well, but they might be different from someone's needs who lives in a different part of the country with different terrain, temperature, humidity, etc. Maybe some folks have a need for the higher capability just to be able to see ole wiley. I don't where I hunt. This thread started out with the author asking about experiences of users of the 50A and 50S. Somehow the thread seems to have drifted off to discussion of IRD. Although interesting and informative, I don't think that serves to answer the original question. I don't want to hamper the discussion, but maybe it's good to remind a lot of well experienced and capable coyote hunters that there is still a question that needs addressed relative to the merits of the two models of Apex. I think there have been some good responses in regard to the functionality of the 50A and to a limited degree the 50S, but I don't believe anyone has mentioned experience with the 50S. I am kinda curious about that model myself. I have often wondered why it is offered and why Apex seems to think it might have value. Didn't see the advantage when I made the decision to buy my 50A, and still don't but would love to hear someone else's viewpoint.