Doesn't Mishh's findings proof this wrong? An Innvocation build using Frost/Mage armour depending on each fight. I've seen his video and his dps is impressive. To me Rop is a really clunky mechanic and just shows Blizz ran out of ideas.
Also am I correct that its not worth thinking of switching unless I have 4 piece?
I am grateful tho for mages out their trying different things out and reporting their results.