My SS/DA Brute hit level 50 during Double XP, so I'm really getting a kick out of these replies.
I have my Heal slotted up pretty well at this point (accuracy is very high, end reduction is down to something like 95%). It's sort of irrelevant, though, because I think I had to use it once, maybe twice, running about six missions on Relentless last night. (I didn't use any Health inspirations, either.)
Dark Armor far surpasses what I expected from the set. Overall, my Health stays at a significantly higher level than friends with /FA or even /Invuln at times, and I can almost guarantee I spent a lot less on IO sets than they did. I expected to be much, much squishier than I am. I was warned of the horrible end use from both sets, but it's very seldom an issue. (Smart slotting is CRUCIAL to Dark Armor, a lot more so than something like Invuln or Electric.) As much as I've dreaded fighting them with just about every other toon I've ever had, Circle of Thorns are a joke with Dark Armor. Carnies are about the only outfit that worry me.
Are your resistances as high as some other sets? Of course not. Honestly, some of the numbers look downright unimpressive "on paper," but when you see them in action, the synergy is amazing.
Here's what I've realized: the Resistances in Dark Armor aren't your "First Line of Defense" like they are with Electric Armor or Invuln. The Resistance shields in DA are, in fact, tertiary defenses. They don't even factor in when the majority of the mobs you're attacking are Feared, Disoriented, or both. Resistance is also not a factor when the un-mezzed mobs are consistently whiffing their attacks off of your Cloak of Darkness (and its "laughably low" defense rating).
Dark Armor is all about damage mitigation. Instead of taking the hits that your Invuln and Electric Armor buddies are taking, you're standing in a ring of mobs that aren't able to even ATTACK you most of the time, much less actually HIT you consistently enough to do serious damage. Of course, you might still take enough damage that you'll be forced to use your Heal -- arguably one of the best Heals I've seen for a melee class -- and you're back in business.
My only complaints with the set are that the res is kinda poor (not a huge issue, I don't usually take enough damage to worry about hitting 0 health anyway), and that Death Shroud uses too much end for it to be of much use to me.