Wait till after the patch today before you decide, they are nerfing the crap out of NPC DDs and AoEs. To many complaining about 100K DD and 128K+ 4 tick AoEs. I personally, found those T2 mobs to be challenging but not over the top.
That's good re bringing down the DD and AoEs of the NPCs.
But my question was... are the MOBs mostly fire resist? Therefore should one switch the rotations to slightly more ice based? Like, for instance, they added some water based spells to Mage set... implying fire resists make mages less effective (so they give them water based spells which I presume have ice resist checks).