Just wanted to pass on a solution. The game we are working on utilizes Dynamic Batching for rendering lots of animated characters on the screen at once. Our performance was great on iOS except for on iPhone 6 and above. When profiling this slow down we noticed Rendering taking a huge amount of time. Tracking down the culprit, it appeared Mesh.CreateVBO was pegging the CPU whenever we had a larger amount of characters on the screen.
Profiling
Render.Transparent
Dynamic Batching Performance on Metal
Profiling
Render.Transparent
->...
Dynamic Batching Performance on Metal