Most of the people I have seen avoid the tanking T10 chest simply because of the one you can buy with 95 emblems, the
Cataclysmic Chestguard, which is so much better apparently. Can't say they're wrong, since a tanking armor piece without defense really doesn't sound appealing. So far I have been using the
Ghoul Commander's Cuirass, and I like it. Plan on getting the Cataclysmic myself when I have enough emblems for it.
I wouldn't skip the gloves unless you get a similar drop from a boss, but if you run VOA regularly you have a fair chance of getting gloves and legs from Toravon eventually. True they only have def rating and hit rating, with extra armor, but you get plenty of avoidance stats from other stuff around, and your combat table coverage will become kinda retarded even before that (something like 80% before using HS outside of ICC).
The 4 set bonus doesn't sound too bad really, Divine Plea is on a 30 second cooldown and you get 12% extra dodge for 10 seconds after you activate it. In fights like Festergut it could be a boon, since his damage at 3 stacks of Inhaled Blight becomes barely bearable, but all in all it's entirely situational.