Amalgam's Seventh Spine (at a reasonable item level) was excellent pre-8.0 but now the mana-return from it is bonkers. I was having mana problems while spamming PWS on the raid, switched to that, and all of those problems disappeared. As an example , the Spine returned nearly two full mana bars of mana over a 6 minute fight, almost 3 times as much mana returned by Shield Discipline.