I have 4 rifles chambered in 6.5 Creedmoor, 2 with 22" barrels and 2 with 24" barrels. The 24" barreled rifles are Vanguard2s, a special run made for Cabela's, and I like them well enough that if I was going to build another, I'd probably do it with a 24" barrel and absolutely not less than 22". I've yet to own a 20" bolt gun that wasn't unbalanced to the rear, even with a light weight stock, and I prefer a neutral balance.
The majority of my bolt guns that came with 20" barrels, Remington 7s, 660s, and Winchester 70 Lightweight Carbines, have been rebarreled with longer barrels as a means by which to improve their balance.
The only scenario in which I can envision myself opting for a 20" or shorter barrel is on a rifle that is used in tight cover or in a tree-stand. My 17" Winchester 100 in 308 is a dedicated tight cover rifle.
