I have noticed a considerable drop in stability in completing Crucible 170 with both the Beastcaller’s Pet Druid & Beastcaller’s Pet Elementalist. The drop in DPS between having the Primal Spirit and not having the Primal Spirit is very noticeable in both builds, and when you have 2-4 Nemeses charging at you, that has been the difference between having the DPS to kill off one of the bad guys and not being able to kill them and the cumulative damage killing off 1 or both of my Briarthorns, causing a chain reaction leading to my death.
Ritualists (including both Ghol’s Acid and Skeleton Vitality) are unaffected because they have numerous other sources of DPS that could ride out the longer wait time. The biggest nerf was to those who relied on both Briars and Primal Spirits simultaneously.
How to change this without making Lightning Conjurers busted again I don’t have a clear answer. That has more to do with the Bloodsworn Codex and Zaria Amulet having perfect synergy with the Kelphat rings than anything else, so if anything I would nerf the MI’s and at the very least return the 5 second duration modifier to the Beastcaller’s Completion set.