Performance? - Unity Trees & Wind Zones or Animated Trees

Hello,

I would like to ask which is better in terms of performance - using unity generated trees + wind simulation OR having custom animated trees (created in Blender/3DS for example)?

To be more specific (if it makes a difference) I am trying to determine which would be better to use in a mobile VR project.

PS: Also, something that might deserve its own question: with the new LWRP, the wind simulation in unity does not affect speed trees /perhaps because of the shaders/. I found this asset on the store -> LINK, yet I was wondering if there are free solutions to the problem or even guide to create lightweight tree shaders /perhaps using the shadergraph/?

Thanks in advance!