Yes exactly.
Well I guess I like 20ac because that's how I learn Nwn. I never played in Sou, I started with Hotu and obviously with 20ac. I've tried 12ac, i even played it for a while but I always return to 20ac. Plus I didn't really approuve when u said it is for lazy ppl because even 20's rule, u still have to think about making a better build then the other. It's not only luck. In 20ac you have to duel the same chars alot so you can actually notice that if you always win, it's because your char build is better. But I do understand your point of view, and yes lower ac and resistance makes it harder to build chars since you have more things to think of into skills and abilities.
20 ac is just who has more attacks per round and dmg pretty much all there is to 20ac