Originally Posted by
Loganisis
Summarizing what I've read on here from those smarter than I...
Hit/Exp is typically only gemmed for if the tank has a threat problem. If you're taunts are landing on fights like Saurfang and you're not having threat issues - you're good where you're at. If taunt is missing, then look at gear/gems/chants for some hit - but you shouldn't need much. If threat is an issue, then look to EXP on gear/gems/chants as it gives more bang for the buck. But again - you probably don't need much - extra threat is like being that much faster than the slowest guy when running from a bear - once you're safely past him, it's all for show.
Typically the recommendation for gemming for Def once you're past he Def minimum is only if you want to activate a yellow socket for a +9/12 sta bonus and use the +def/+sta hybrid gem if they don't need the +hit/sta gem for the hit rating. Otherwise health and armor are considered the key stats in ICC, so gemming for Sta is considered the most valuable gemming policy.