I originally tried to model the pylons inside TG2 with displacements, but because there are displacements on top of displacements, having a couple of Compute Terrains really, slowed down the render. So I just did some quick modeling in Max, used it in TG2 as an OBJ object, and the render sped right up again.
About the flat background...yeah I was being a little lazy there...hehe
As I have a few PC's at my disposal, I rarely worry about rendertimes for final renders, as I just turn up the settings and let it go one one machine. But If I remember correctly:
Detail: 1.05
AA: 12
GI RD: 2
GI SQ:2
Rendertime: 5 hours (dual proc)