I pulled this over from the Stalwart Defender discussion:

Quote Originally Posted by LeLoric View Post
This is pretty much my concern too. The average tank isn't going to hit 90+ ac consistently. And this is the normal quest requirement to really see effectiveness.
Bear in mind, and LeLoric can correct me if I'm wrong. He's talking about the "NORMAL" quest requirement, which in the rest of his thread he states as being rather high at that level.

Quote Originally Posted by LeLoric View Post
Defenders and twf ac characters would be fine if the ac thresholds were fixed and the easier method of dot and shield block is brought into check somehow. It's really that simple but unfortunately because DDO and the d20 system is step based and not continuous there is really no middle ground so they go from being ok to having really little use anyways.
I'm not sure where LeLoric stands on the Wings issue, other than he'd rather not have Chains be spammed, but the above statement makes no mentioned of Leap of Faith or any of the other "Flight/Jump" abilities. He specifically states that the DoT/Shield Block method is easier, and should be checked somehow. It is not Leap of Faith that is the game-altering tactic that it seems to have been perceived to be.

Quote Originally Posted by LeLoric View Post
Look I don't want to be able to sit there and take no dmg whatsoever it's pretty boring but I also want there to be a reason to use an ac based tanking character. If there isn't going to be a reason to use it then I'd suggest the devs stop devoting resources to these types of characters, lots over the last few month's led me to believe they wanted to make s/b ac tanking viable again. New feats for shield users. Changes to intim to make it a more active play style.
This is a call to address Tanking and Tanking Classes and Prestige classes to make them viable not only in the new Raids but elsewhere. I personally still see tanking, but as I do not play one, I'm not aware of the challenges they're going through to stay "in the game" so to speak. One of the best I know is a Paladin/Rogue Evasion Tank, and even he admitted it was a carefully planned build.

Quote Originally Posted by LeLoric View Post
However when the chance comes to implement the changes they made into working content they dropped the ball. There is little to no reason still to use an ac defender in Master artificer due to the mechanics of the fight. For Lord of blades the opportunity is there but due to high ac thresholds and inability to do a better job than shield blocking dot casters and barely better than 0 ac barbs and even then only on normal. I find myself upset maybe because recent development had given much promise and potential and now I see all that wasted.
Once again, the mention of DoTs in play. No mention of Wings, and no specific mention that these are divine DoTs, just casters in general. Again, LeLoric please correct me if I am misreading the results of the test. The mechanics of the Raid, and indeed, Defenders needs to be looked at. Even the DoTs should be under review, not simply a single ability that happens to make Kiting a bit easier, because there are other easier to acquire abilities that make it just as easy, as has been previously mentioned.

Quote Originally Posted by LeLoric View Post
In no way do I think that s/b should be the only tanking method btw. I'm fine with barbs tanking but what I think should be the case is a s/b character should be able to dramatically reduce dmg taken in exchange for the lower dps and longer completion times. I do take issue with the ease of tanking alloted caster classes though. I think they own enough of the pie too but further grabbing a large portion of the tanking dmg absorption pie is leaving only few crumbs of the pie left for the big melee types.
Mmmm Pie. But I digress...even here, there is compromise, but the idea of a Caster tanking just seems odd to me. As I said, perhaps I run with reasonable types that like a balanced party, I don't know. I have seen the DoT/Block that people are talking about, but honestly, not too terribly often. Favored Souls, whose damage output does not match Arcane DoTs, aside, there seems to be a flaw in the root-cause analysis here.