First portion of the third area (in the black full plates): Crits are all 1 shots. Give 0 xp. Appear to have similar drop tables as 2nd area, but have not tested too much to determine what else drops.
Cannot get into the 2nd portion of the third area yet (says we "are not strong enough to be there"). However, crits will roam past the "boundary" wearing gold fullplates. Cannot connect with skill "41+" FM with psionic diversion and divergent essence and flame spear. Also tried some of the new weapons (skill 40 as well) and could not connect either. Also tried with skill "41" barb, and 40 pally. (Brad is aware of this bug, after you hit 100% the skill continues to climb into the 100's without giving skill 41, then bugs out after so much and starts reporting -120% skill and counting down backward, after it hits -70% or so it then lists you as skill 41 but shows your age as the skill description "very young" and sticks at 100%). Creatures in this 2nd portion of the third area do give experience (lots of it) but are 1-shotting zerked barbs with 13k+ hp.
Perhaps tune-up the first section of crits and give them experience (so it's worthwhile hunting there?). I'm guessing the 2nd section is tuned so high because of another requirement (hence the "not strong enough to be there"). I could be wrong though.