I would like to know how many of you use large calibers. i.e. 308 and above (just curious)

I personally do not. In some areas there are restrictions to what size of calibers you can shoot for varmints and predators. Here it is anything from .17 up to .270.

If it's a Hog I'll shoot anything I have on hand. Most of my varmint hunting is done with a 22-250. I sometimes take my .260 Rem on 'yote hunts.
The small critters are dispatched with one of my .22 rimfires.

I dont use one but I have shot one the kick really bad, there nice but there not one you wont to shoot all the time.

Prairie dogging, I'll take everything from my .223 up to the .50 BMG. Coyote calling, usually just the .223 or .243 and a shotgun. I really want to find a place that is a short walk from my Jeep so that I can get setup with the .50 though!!