If you are currently sitting at 500 AR, then 80 AR will give you roughly 11% damage reduction from everything, 7% reduced damage from elites (as can be found on blackthorne's boots) will give you a 7% reduction from elites. So yes, AR is always better than reduction from elites.
One data point surely does not cover all.
However, the point where 7% damage reduction = 80 AR is at -25.31 all resist. And as the data point above shows, anything higher than that, AR still beats DR, so we can assume that for DR to be better than AR, you'd need less than -25.31 resist all.
NOW you can say 80 AR is better than 7 reduction. But, of course, both is even better :)
EDIT: Forgot to divide out a factor, whoops! It's still negative and unreachable, though.
what if im sitting at 900+ all resists? 7% damage reduction from elite will be far better then?
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