What makes you think cap is 567? Not saying that is wrong, but how would you know that? People keep stating it but no one ever says how it can be checked.
567 is the amount you need to get while using a shield, ~670 AR is the amount without using shield. Its easier to hit the cap without shield with heavy armor but if your a shield user then that dosnt matter and it boils down to the perks. (there is a thread in cheat section where we tested and made the math for this) http://www.gamesas.com/index.php?/topic/1289727-2419-armor-6399-damage-using-smithing-alchemy-enchanting-only-33-perks-329k-backstabs-post-4/
Light Armor has the benefit of gaining "0 armor weight and no speed penalty" and "+ 50% silent movment" quicker than heavy armor.
50% stamina or stagger is pointless both ways you wont even notice it working in-fight.
10% damage avoided by light armor means you have 1 in 10 chance of avoiding ALL incoming damage while heavy armor only hits the enemy for 10% of the inoming attack while still getting hit for ALL the incoming damage.
Light Armor wins here hands down. :intergalactic: