We use the untiy3d engine. We use version 3.5.0 and the Ellipsoid Particle Emitter of the Legacy Particles with ios target platform.
Heavy use of Mesh Particle Emitter, small number of particles and size, but many emitters, all parameter set the same, how to optimize this kind of particle emitter?
I made the experience that sprite animations are performing better in that kind of situations when running on iPhone. See SpriteManagerdead link or Animating Tiled texturedead link for example.
Another approach might be to combine both techniques via LOD