In a mad fit, I've bought all three flat Armor Quintessences for my physical rune page. The provided armor total adds to 22 bonus armor; I'm frequent Sion who starts out with 23 armor; were I to start with Cloth Armor and health potions, I'd get to lane with 60 armor.
I already hear you saying "You should use your Quintessences for damage or anything but armor". But I spent 3000 IP in a mad fit, and wanted to try this out. So can this work?
IcyPepper2 votesYou'll shrug off physical damage poke easily, so there's that. You won't deal much damage, but you'll be in lane forever before your first b.
At least you can rush a damage item without having to worry about your defenses.
50000000000000002 votesI thought you were going into jungle at first (in which case, 60 armor sounds good. Without 
it would still be 45 armor. Not bad).
As top laner, as long as you aren't up against AP top laners, that sounds like a great start.
EndlessSorcerer2 votesSituational, though they can be strong. I typically use them in top lane to survive tough matchups or when I want to deny my opponent the opportunity to snowball. 60 Armor might not seem like a massive amount, but it will make frustrate many Riven, Renekton, and Rengar players since you are so hard to whittle down. Your damage might be a bit lower and cost you a kill sometimes, but you have a massive amount of early sustain and durability so that you can farm up safely for your core items.
I also typically use them on tanky supports such as Leona, Alistar, and Thresh. You don't really need much in the way of damage in runes to do your job and the extra armor helps you endure poke and minion damage when fighting early.
Could be used for some cheesy picks too. Back when Riven, Zed, Kha'zix, Rengar, and Wukong were popular top laner I would often take Taric into the top lane and get around 80 or 90 armor at level 1. They are good on Poppy against an physical damage champion for early fighting, especially when combined with her W passive at level 1.
Keep in mind that for everyone I suggested, you could easily use Flat Armor Quints and Scaling Armor seals for strong mid-game armor. The scaling match the flat seals at level 6 and most AD casters need level 3 to really fight effectively, so you don't really lose much by doing this.
ProfDrDeath2 votesI also have Armor Quints, but I mainly use them on tanky supports. My tanky support rune page actually looks like this:
Armor Reds (91% of yellows - I only lose 0.81 Armor for running reds instead of yellows) Scaling Health Yellows Flat or Scaling MR Blues Armor Quints
Dreadlocks1 votesArmor quints are good.. Not sure about them on sion though.. I suppose if u know ur gana lose lane? or get heavily harassed ex: quinn?
Laraso1 votesI start the game with 102 armor as 
Ironclad Dragon1 votesI assume all of your runes are armor?
Very Hard Engage1 voteshealth is more important early on, that extra 72 health is an extra hit from an adc, where as another 9 armor is roughly 6% mitigation early in the game, so 72-6% isn't all that much.
as rammus or taric/healer i would consider the extra armor runes, due to passive/heals. other champions i would go for the health yellows.
MLDzXnRRR1 votesTaric top with such rune page + masteries makes all the riven/ fiora etc players cry.
Blue Collar Bear1 votesIt certainly works. The first time I started using armor quintessences in the jungle, it was because a friend of mine in high platinum swore by them.
They are extremely slot efficient runes that do a great job at mitigating physical damage. If you're going to start Cloth Armor and you also have flat armor quints, I'd recommend taking scaling armor yellows. It doesn't take long for them to kick in and you get a lot more out of them!