The pros of a clip on. If you have a great, accurate rifle, with a good LPVO style scope, and you want to use this setup day and night, then a clip on would be a nice option. The things I don't like are they are more expensive than their stand alone counter-parts, if you want to use as a scanner you have to thread on an eyepiece, they add weight to the gun, and to me a really big issue is the focus is in front of your day optic so not exactly convenient to operate. There are many on this forum that love clip-ons. I am not one of them. However, if you are indeed set on a clip on, both the Hogster C and Yoter C are good values.
You should probably start with what your intended use will be for the thermal, min-max and average shot ranges.
I have tested and used every current Bering model including the Stimulus, 25, 35, Super Hogster, Super Yoter, Hogster c and Yoter C, and the Phenom 384 and 640. I not only test thermals but actively use them. I shot over 300 coyotes last winter so I have a lot of field experience as well. If you have any specific questions feel free to send me a PM, and I can provide my cell number and we can talk. I get $0 of commissions on sales so what I tell you will be from my experiences and have nothing to do with trying to sell you a thermal.
Korey Kirschenmann
Night Goggles: Product Specialist
