it would take me a very long time to create the kinds of scenery I have seen in the Infinite demo
Me too - that's why I bought Vue :) Modeling dense forests and such has been (and still is) hard to do even with MAX, XSI, Maya or Lightwave.
Is the content which comes with Vue any good for creating those lush natural environments?
Sure, what you see in Eon's Vue 5 Esprit section can be done with it. You get same amount of species as in Infinite, but can't edit & save them (create new ones). But even if you create 5 palm trees in Vue 5Esprit they are all slightly different - not clones of each other.
Ultra-realistic SolidGrowth vegetation:
Esprit: 52 species
Infinite: 52 editable species