Wow... just wow...
Also, I'm now of the opinion that the whole right side of the Smithing tree isn't worth it. Daedric weapons only have a 2- or 3-point damage advantage over Glass weapons and a 1-point-per-piece armor advantage over Dragonplate, even though it takes the exact same number of Perks to get Daedric and Dragon Smithing. On the other hand, going with the Dragonplate smithing gets you the option of making strong light OR heavy armor (useful for followers), and the slight differences in the base numbers really pales once you consider that even low-end improvements increase the base damage of weapons to the point where it's kinda silly to worry about these.
Unless you massively grind smith early, which most do, i know, it doesn't matter either way. Once you get to Smithing 100, if you level up more or less like the game intended, alchemy & enchantment will also be pretty high, meaning you can just craft yourself the most awesome smithing gear, and smith yourself dragonslaying weapons of doom and armor of the gods from common iron. And look badass while doing so, because i really like the low-end armors & weapons look better than i do the higher end ones.
Really, the armor cap is so low, that with just 447 combined armor from items (actually 667 displayed armor, because of armor bonus when wearing multiple armor pieces), you reach it. 80% damage reduction all day.
Heavy Iron Armor is 25
Iron Helmet is 15
Iron Boots is 10
Iron Gauntlets is 10
Iron Shield is 20
Smithing to Legendary gives +20 to armor rating, and +10 to ratings of others
Grand Total: 140
Still 307 shy from the grand total. But that's not all...
To smith to Legendary, you need exactly 91 smithing. Every point after that, increases rating by 0,1 for armor, and 0,05 for every other item.
Assuming 80 heavy armor & block, with 5 perks in Juggernaut, 1 perk in Well Fitted, and Matching Set, the formulae for deriving the displayed armor rating is thus:
(worn armor rating + item quality) * (1 + 0.4 * (skill + skill effect)/100) *
(1 + Custom Fit or Well Fitted + Matching Set) * (1 + Agile Defender or Juggernaut) +
(shield armor rating + item quality) * (1 + 0.4 * (skill + skill effect)/100) *
(1 + Custom Fit or Well Fitted + Matching Set) + armor effects
If we calculate our displayed armor now, it will show 236, which is 431 shy of the sweet spot...
But never fear, for Enchanting and Alchemy will come to the rescue.
With 100% Enchanting, the appropriate perks & 5 grand souls, make yourself a 4 piece set of Fortfy Alchemy gear. Actually, glitch that Falmer Helmet (Put it and a circlet simultaneously), and make that 5. They will all have 29 points worth of effect. This ends up at 146 points of fortify alchemy, w00t.
with your newfound 246 alchemy skill, go and make yourself some potions of Fortify Enchantment...
Once you have super potions of Fortify Enchanting made with your super gear of Fortify Alchemy made with the help with the less super potions of Fortify Enchanting made with... You get my drift. Only 4 or 5 iterations should give you a 40% strong Smithing Enchantment, which is quite enough. You can slap the Notched Pickaxe which gives another 5 points, just for good measure. Oh, also make super potions of Fortify Smithing, along the road.
With your 400 some smithing, go and re-smelt your weapons. It's like Lord of the Rings... The elf takes a thousand year old broken blade, apply some hit, and suddenly... NARSIL! CUTS THROUGH STEEL! Hey, it even rhymes.
Since your smithing will be so high with the help of items, you can even neglect it a bit, since the perk for Iron Armor requires nothing but base.
Just choose the armor you think will look best, and never look back, unless you're planning on using SPECIFIC ARMORS (I.E, unique armors), like the one from the Dark Brotherhood quest - then you need to get the specific perk for easing the requirements for Legendary + perk and get the Arcane Blacksmith one, both of which require higher actual levels of smithing.
This doesn't even take into account effects such as Fortify Heavy/Light Armor enchanted onto the items themselves, which pushes the barrier for this trick even lower. You can really run around in that bandit Hide Armor enchanted to all-hell and smitten to all hell, and never look back. And you can find 20% strong alchemy gear pretty early into the game, which helps with the iterations and ingredient gathering. Fortify Smithing potions have appeared for me up to the 50% range, but with mild investment you can make yourself ones that not only last longer, but go up to 60+% effect, with no iterations of the trick. Fortify Smithing gear is plentiful in the 20 point range, too.
A good point to note when you have the necessary levels, perks & items to change from Daedric whatever to sexy looking iron without getting beaten to hell and back by Giants, is just noting what the displayed armor rating is with your best armor, and subtract the difference between it and Iron Suit.
Iron Man suit goes to 60 with no shield
Daedric goes to 108 with no shield.
A mere 48 point difference. So when you're rocking 823 displayed armor with that ugly ass Daedric shit, you can change to sexy Iron Man with no problems, since the gains from smithing are equivalent no matter the armor quality if you have the required perks from both smithing and armor.
With the procedure i outlined, you would rock much more than 823. Well into 1200 or so. Even more depending on your patience.
So, yeah, i choose my armor based on how good it looks on my character. I like Plated Steel & Iron most of all, but if i can afford to lose the 25% from matching set, i actually combine some Orcish into the mix, especially the boots & the helmet, which rock so much. Ebony also is pretty awesome, apart from the helmet, and i especially love the shield.
What i said works for weapons, too. Choose the sexiest one, and the perks & high smithing will do the rest. Some 30 damage will inevitably be lost between high-end Daedric to primitive Iron, but when the weapons are dealing 250+ damage, does it really matter?
The problem is some of the coolest weapons aren't in any perk, like the Ghostblade, or can't be smitten, like the Ancient Nord/Ghostly Ancient Nord stuff, and some other uniques.