Calculating max critical dmg on a Hero

My crits are higher than my non-crits, so can't say crit is utterly useless for a Hero.
I prefer to wear my Cruel ring rather than my Crit ring, but that's based on pre-bb recommendations (which said Crit ring is only better when under SE). Haven't actually done or seen any math post-BB (or post Chaos).

I'm also curious as to whether a %crit line on my weapon is a significant increase in DPM, or I should try for %dmg, %att, or %str instead.

cruel is worse post bb/chaos. %crit damage is removed from the rings so critical is easily the best ring due to its crit rate. And if i'm not mistaken %attack and %damage are always significantly better than %crit on a weapon.

Crits as a whole aren't as strong post-bb.