Need help with this Barbarian Variant

[Ashtagon]

I'm a firm believe in the idea that any "you gain ability modifier X to bonus Y" class features should be capped at your class level; otherwise, you encourage level dipping.

With a decently-optimised character, you can quickly expect to get +4 Con bonus, which makes up for the basic armour bonus. You are also gaining the benefit of not suffering the skill penalties of the maximum Dexterity by armour type limit. Additionally, you gain about 20 lb or so of encumbrance capacity if you use that rule, and not worrying about sleeping in armour.

Against that, you lose the potential for most forms of magic item that would have gone in the armour slot. There are substitutes for those items, but how available those are is very campaign-specific.

Overall, I think this leads to a slight power-up if a low-magic campaign, or a nerf in a high-magic campaign.