TG2 is slow but it's more realistic.
You could try faking 3D clouds more in TG2. I've not really tried this but I did do it in Mojoworld. I got sick of the volumetric cloud rendering times and actually hardly ever did any so I faked 2D clouds to look better, mostly by having the 2D layer so high above the planet that you couldn't see the flatness. I'm not sure if this kind of fakery can be made to works in TG2.
The best thing in Vue is the vegetation. That is used a lot for movie matte paintings. Volumetric clouds are rarely used due to render times and clouds are quite easy to paint in at post stage.
Thinking now, it probably wouldn't work well in TG2, just to raise the clouds, due to the TG2 atmosphere.
Another trick might be to render at lower settings then fix in post since clouds are whispy and easy to post edit. Some kind of compositing maybe.