[Tanking] Conviction + Persuit of Justice vs. Reckoning

I am considering changing my tank spec to this. I remember when I hit 80 on my pally reading not to take Reckoning due to parry haste, but I think the TPS is worth the parry haste. It's not like I'm lowering my defense to 534 to risk for crits. I'm just slightly increasing enemy attack speed(until I reach hard expertise cap that is, haha).

I wanted to know what TankSpot thinks. Maybe this is the norm? I didn't see a Prot threat on elitistjerks, which is where I usually look for spec advice.

For clarity, I am currently 3/5 Conviction, 2/2 Persuit of Justice. I am planning on dropping those and going 5/5 Reckoning for tanking purposes.

What does your spec look like now, and what are you planning on changing it to? A talent calculator might illustrate the point I'm about to make.

Conviction is a weaker threat talent than Reckoning in ICC gear (Reckoning being nearly twice the TPS per talent point as Conviction), and only two bosses in ICC seem to be parry-hastable at all, but 5/5 Reckoning has a pretty high opportunity cost. If you took your points out of the Ret tree, would you have enough left to still pick up Crusade? 3/3 Crusade is a huge threat boost, particularly in ICC, so going from 3/5 Conviction + 2/2 PoJ + 3/3 Crusade to 5/5 Reckoning would probably end up being less threat overall.

If you do want Reckoning, the more usual way of picking it up is to drop Divine Sacrifice and Divine Guardian to go 3/5 Reckoning. I don't think the minor TPS gain is worth the big utility loss, but there you go.