How accurate a rifle shoots is more important to me than barrel length. I've used varmint rifles with barrel lengths from 16 to 24 inches. I actually prefer the shorter barrel rifles when I'm doing a lot of walking, or hunting in heavy cover. It all depends on where and what you're hunting. If shooting prairie dogs, where you're shooting off of a good rest, then a long barreled rifle would probably be the best choice. But, if I have to walk several miles in cold weather, wearing a lot of clothes and carrying some gear, then I want lightweight rifle.
I shoot the Remington Model 7 Predators a lot, they are 22 inch barrels. I use them more than I do anything else, mainly because they shoot so well and I just like them. I also have a couple of rifles with 20 inch barrels that I hunt with as well, and I carry a 16 inch barrel AR on occasion. I've killed stuff with all of them. To me, the barrel length is last thing I worry about.
