Defiance v. Invulnerability

I hit 23 with my chainsaw wielding lumberjack the other day before the free power reset on Wednesday. I had used defiance up to that point, and for kicks I picked up invulnerability. I was fighting the Godron in Canada which were +2. Invuln was providing far more mitigation than defiance did, even with a full stack.

Defiance Vs Invulnerability...

I have discovered rather painfully, that there is no contest here, the difference is comparable to a fist fight between an infant and a grown man, in perfect health....

I made the Switch(From Defiance to Invulnerability), but kept my Defensive Combo, Power, which still provides "Defiance" buffs, in addition to Invulnerability's Static Dmg Resist...

I read a lot more on the official boards. Defiance is supposed to cap at 40% defense for a full stack. The playstyle to do this is to use the ranged taunt from a melee energy builder then shield block and wait your 20 seconds or so until the stack is up. Defensive combo was nerfed this patch so that it only refreshes/adds one stack of defiance. Previously defensive combo had been able through spamming to hit the defiance cap faster than the slotted passive defiance, and invulnerability people were using defensive combo in addition to invuln to effectively have two strong defenses.\

To also play defiance properly, you need to carry stacks into the next fight. So you drag along a henchman and let him whack you as you move into another group.

TO me this is very cumbersome. Invuln is supposed to cap at around 28% defense at rank 3, to which there is a flat subtracted damage. It is good right out of the box with no buildup or wait.

I am running Invuln with Defensive Combo, and am enjoying both powers defensive benefits...

Invuln for me at lvl 22 with a Con of 106 is providing me a 31% Dmg Resist to all, my Slotted equipment provides me another 23%, and I see the Defiance buff all the time (though only one application of it *no stacks)
I am unsure what Defensive boost one application of Defiance provides, but I like to think its about 8%...