I'm not really a magic-user myself (though it's fun to have a mage or two in the party when I'm playing with friends), so my opinion might not mean much here, but I really feel that the Eitr armor would be better if it actually added to your base eitr and not just the regeneration. Something so that you're not just totally reliant on foods, y'know?

[EDIT] In other words, just like OP said.