Personally, I wouldn't want anything under 14" without a suppressor.
I've shot some shorty AKs, unsuppressed short 5.56 ARs and had a 16" 308 with a noise-maker on the muzzle. They were my idea of hell to shoot. I might as well have driven nails into my ears.
I agree with you. Hence the reason I shoot rifle length gas systems and 20" barrels. Anything else makes me feel like my noodle is getting knocked loose. It even takes my eyes a while to adjust after shooting crapbines. Just don't prefer them...