WotLK Armor or avoidance.

[Persivaln]

Sure pal. But small hint to you. Raids want stability and consistency. So you'd rather have tank that can survive 3+ hits from HC Boss, that squishy maggot who dies to third hit due to "bad luck".
Armor stat is hugely underestimated, while being most efficient thing in WotLK, that up-scalrs stamina to even bigger value over avoidance.

[SilverFlash]

Well i do gruns not pugs and my pala tank did till synra hc,and it was not tanking prob it was more prob of tactics,so i never got kicked.Well u build what u think its best i mean 11% more avoidance over 2% reduced physical dmg.

You get into a bad rng session and you'll take much more damage than just going ehp.
I'll take that 2% reduction on Sindy's ~75% worth of damage,and the extra stamina for her burst damage(Frost Breath,at least assuming no dumdum melees to cause extra parry-haste hits) over some what if avoidance.
I bet if you ask your healers,they will prefer high but constant,predictable damage to heal over spiky random extreme damage from unavoided hits. The less OH **** moments,the better(especially since paladins lack good cooldowns that don't screw each other over and don't have one hundred billion year cooldown timers).

As Persivaln said,armor+stamina/hp is the meta for wotlk tanking(except for anub hc,but if your guild is steadily doing anub hc,they'll have a warrior tank ready geared specifically for that fight).

[anovakm]

Well i dont care for syndra hc coz we have DK.Its much better for dk to tank it than pala.