Seventh Ring of the Tirisfalen vs Karazhan Rings  

Italics are creative writing, see the gear comparison below italics.

She was hard, yet feminine. The Astromancer stood in her crisp sharp uniform looking cold and indifferent. An aura of boredom danced in the air about her, though I knew it was certainly a guise, just gazing at her I could nearly feel her readiness.

I stood there measuring my target just out of her sight, the members of my party gathering behind me in the shadows. Looking at her I could tell she would be merciless and cunning, a spell slinging witch. Yes, that one was dangerous.

It would be my job to keep her attention, to distract her while her reinforcements were dealt with. It would have to happen by surprise. I would have to use both my appearance and ability to startle her, to keep her attention... taunts would be useless on this cold calculating beauty.

...

She was not long for this world. She collapsed her hand raking the air as though to drag me down to the depths of hell along with her poor damned soul. As she breathed her last, the light caught a glint from her hand...

[Seventh Ring of Tirisfalen]
Binds when picked up
Unique
Finger
+37 Stamina
Requires Level 70
Equip: Increases defense rating by 17 (7.19 @ L70).
Equip: Increases your shield block rating by 24 (3.04% @ L70).
Equip: Increases the block value of your shield by 24.

I guess I shocked a bunch of people because I passed on it to another tank. The other tank was a person that I've known for a while yet and he's always been generous with me. I was a bit surprised myself that so many folks thought it was such a big deal!

Yes the ring is very nice, but it's certainly not nicer than the Ring of the Stalwart protector that I could get from badges:

[Ring of the Stalwart Protector]
Binds when picked up
Unique
Finger
392 Armor
+45 Stamina
Requires Level 70
Equip: Increases your dodge rating by 28 (1.48% @ L70).

AND it would be a side-grade to what I am currently wearing:

[Shermanar Great Ring]
Binds when picked up
Unique
Finger
223 Armor
+36 Stamina
Requires Level 70
Equip: Increases defense rating by 23 (9.72 @ L70).

"Well... how do you figure it's a side-grade?" You ask.

Here's why:

The Seventh Ring of Tirisfalen causes me to loose approximately 220 Effective Health and 0.31% Avoidance it only adds 24 Shield block value as compared to when I wear the Shermanar Great Ring. Don't get me wrong, I will still pick it up as it will be a welcome addition to my threat set, but since I have 39499 EH and 64% avoidance right now EH is a primary concern for me.

When I do replace the Shermanar it will probably be with the ring of the stalwart protector which will net me roughly 474 EH & 0.25% Avoidance.