Now, I may seem the noob here, but over the past few weeks I've been learning a lot more about tankadins and our gemming/enchnting priorities. I don't quite know the biting point for diminishing returns on dodge/parry yet, however I do know that overall, agility is better than dodge. I've been reading Elitist Jerks threads (before nyone says anything, I do know that most of their data is older and outdated, yet I'm not quite willing to discount it entirely), as well as some threads on Maintankadin.com. I'm pretty new to theorycrafting, though I have a lot of combat experience, having geared myself for Naxx without guild help back before Ulduar, through 6 weeks of 3-7 heriocs a day, and not letting myself get rusty since then.
Here's my Armory link: The World of Warcraft Armory
Ive been asked several times why I don't gem parry more, and I've not been abble to come up with a suitable answer. As you can see, I have one parry/stam gem, and I've been tempted to go for more. I'm shying away from stam stacking because I feel it isn't as effective as gaining avoidance/mitigation. I used to stam stack before ICC, and got a lot of trouble for it from several people in my old guild, as they were of the opinion all tanks apart from druids should be pure avoidance. I've since come to the conclusion that they didn't know what they were talking about, yet I want clarification.
Long story short, I'm bloody confused, and could do with some advice from some tankadins that actually know what they are talking about. :)