Worldbuilder is pretty hard to learn, it's aimed at professionals (much more expensive as well). At least the last version (2.2) was, haven't tried version 3. Bryce 5 isn't out yet but I'm pretty sure it will be quite like version 4 and that's pretty easy, it has a weird non-standard interface though. I would say Vue 4 is the easiest of the bunch with an easy to understand interface, ready to use vegetation and so on... Just my 2 cents (or euros ;) /Jesper