Thanks for the comprehensive reply Paul :-)
I will download the demo and have a play over a few weekends. I am a bit of a detail freak so from what you said the plugin will probably appeal to me. My main concern is with UV mapping, textures and scaling, not so much the geometry, as with most plugins that generate meshes or imports its usually just a case of removing what should be hidden edges or flipping/unifying normals . If I am on a deadline, I don't want to have to spend a lot of time mapping detail to trees when my main focus should be the clients design, so was hoping for a foliage generator that can drop objects into place with the UV mapping already scaled and orientated in the right place/direction per branch/trunk saving a lot of time. From the sounds of it I will have to build up a portfolio of trees and shrubs over time that will be the detail I want and ready to go in iray, but It still sounds like the plugin will be very useful, Hopefully the GrowFX UV generator works well with iray.
I will let you know how I got on with the demo in a few weeks.
Thanks for your time.