What do you use the PreloadParticleSystem for? The wiki says that it "Preloads a particle system".
I still don't understand :/
It loads the particle system at the start rather than when the function is called.
I think.
In a nutshell: Reading from disk is slow - therefore it is better to do the reading from disk on the loading screen, rather than interrupting game-play with a lag-spike while the particle system is loaded.
So if you are creating particle systems through script then it is generally advised to pre-load them in your OnEnter event. Same logic behind preload sound.
Thanks