I'm in a small guild that is up to 4 Horsemen in Naxx. I dabble in 25 man Vault and OS whenever I can PuG. I MT 10 man Naxx. Overall I like my gear but I feel like I could do better, especially with threat generation.

Here is my armory link:

The World of Warcraft Armory

I also have Skadi's Iron Belt, Inexorable Sabatons, Repelling Charge, Skull of Ruin, and Lavanthor's Talisman all sitting in the bank. I've been doing research on block sets but haven't quite figured it out. Should I try to work any of these into my set?