Bit the bullet and bought the chest. It's the best deal by far. Funfact : wowhead lists only 2 tanking rings, one from chimaeron and one from VP vendor. So you have to buy the epic ring as a mandatory upgrade eventually.
We got a spell casting ring. Considering there is a strdps, int dps, int heal, agi dps, tank version and the fact that the ring only drops 20% of the time, it will take insane luck to get what you want.
There's even a mastery/parry Permafrost signet from Conclave, which dropped for me last week.
BTT: I bought the Tier legs yesterday, since Argaloth refused to drop them and my current legs (346 blues) didn't have neither blue (quality) gems nor the "big" leg-enchant. So overall, I got a plus of about 3k hp and a littlle bit of avoidance, which was by far the biggest update for me. I'll curse the day argaloth drops the legs though
Purchased the legs yesterday after killing Argaloth & Atramedes and getting the head of Valiona because getting the plate pants with the right enchantment from Al'akir seems pretty unrealistic to me.
I'm still wearing my three crafted blacksmithing pieces besides blue shoulders (trashdrop rate in general is pretty low for us) and gloves and looking forward at Cho'galls loot today, purchasing either gloves or ring next wednesday (after killing Argaloth again).