So Ring of Peace is now only castable on friendly targets, and the silence portion only gets applied after a harmful spellcast. So it is absolutely useless against a healer, and any caster hybrid will simply switch to bombing heals when RoP is cast on them. That only leaves non-hybrid casters (mage and warlock), who can simply use non-harmful spells such as Blink and Demonic Circle: Teleport to get out of the Ring of Peace and then they can resume casting as normal.
So the silence portion is basically useless in high level play and it's basically a disarm on a 1.5 min CD. No thanks, I'll take Leg Sweep for a 5sec stun on a 45 second CD because it works on all targets, not just the subset of classes who are affected by disarms.