Quote Originally Posted by The_Jackal View Post
As Arbitrarity points out, the discount/regen enchant is a bad choice, because the skill bonuses to effect only apply to the mana regen, whose full effect is only applied out of combat.

At 100 enchanting and your centerline perks all chosen, you can put 2 effect on any one piece, as long as they're not different, as TheEmerged says. Each fortify school enchant will be 25% (max skill, centerline perks, grand soul), before taking Fortify Enchanting potions. So four pieces of fortify school will reduce that school's mana costs to zero, making mana regeneration (as well as any characteristic increases to mana) totally redundant for that school.

As for fortify block, given that you can quite easily cap out your physical resistance through armour (567 worn armor rating gives 85%), with the right investments into enchanting and smithing perks, in virtually any suit of armour, I'd say that the marginal gain from fortify block is amazingly low. Instead, I'd drop fortify health and resist magic on the shield, ensuring that you're capped for magic resist and just generally tougher.

Having played a dual weilder and seen how invulnerable you become with maxed armour, maxed magic resist and high health, I don't even know I'd bother to perk blocking at all. Vanilla bash is usually all you need to stagger enemies trying to power attack you, and at that point, all you're carrying the shield for is another enchant slot and bonus armour.
Block actually stacks multiplicatively with armor, which is VERY useful. Cutting damage to 3% from 20% is great, especially considering, say, Draugr Death Lords deal something like 300 base damage with arrows on Master. You can shrug that off while blocking, but if you try to tank it, even at armor cap, it chunks your health a fair bit. Of course, you don't need to perk block at all to hit the block cap, with an enchantment, so meh.
Mind you, I still don't really get that much use out of it. Mostly good for tanking Dragon fire, though I bet Spellbreaker will come in handy when I pick it up.