First, your question, for some fights, especially heroic raids, Gargoyle is very nice, and that is a question of opinion, but some tanks like that more than swordshattering.
About your gear...lol...your gear and mine are really close, besiedes a few pieces, like 2, we have exctly same gear.
I would suggest you to not break your 4 pieces bonus, till you get the sencond piece of T12, you are losing a little of dmg/dps with that.
http://us.battle.net/wow/en/characte...angoo/advanced