Well even if you don't get the recast from crit dots, you still have a 100 potency aoe on an off gcd timer, so, in theory, you get more AoE? You have an ability to supplement quick knock spam. \o/
Well, yeah, the conversion of Rain of Death from a button you'll basically never use ever to a button you'll use once every 15 seconds is nice, but the recast thing is just odd.
(It also makes RoD something you'll pop in single-target situations now, since a 100 potency oGCD is a 100 potency oGCD.)