Funny how Vue's fractals can be tweaked to every single parameter, but still can't look as good as TG's , which are the simplest around, and have only a couple of parameters to work on ( I'm talking about TG 0.9, not TG2TP) and the render times are not so high, I disagree on this. But as Bobby said, no vegetation in TG 0.9, and if you want to go the TG2 way, then you're in for a massive headeache, frustration, and long, long, long render times.
TG0.9 had cool plug ins for water, like shorelines and waves that Vue can do, but TG does it a lot faster. But the in new version these  plugins don't work anymore.
TG's renderer is fantastic, I agree, but when I see vegetation in the Terragen gallery, most of the times, I feel there is something wrong with the shading/anti aliasing/level of detail in the leaves, I dunno, but there is definitely something that isn't quite right with imported objects.