Glad you like the shots, gentlemen. I have quite a few now

So the good new is that the High res landscape textures in themselves seem to have minimal framerate impact, if you have a reasonable gfx card. What eats CPU resources, however, is the number of objects you have on-screen. A busy area can have 10,000+ and this is a genuine challenge. So there are some tricks we can play here, but that's what we're fiddling with right now.
It's all iterative, this stuff. As PCs become more powerful and we learn the bottlenecks we can push things forward.
I suspect that some areas will be densely populated with objects for 2.10 but most won't as the objects are very carefully mated to the underlying textures so a random scattering would just not work at all.
Autogen forests will be universal though. You can tune density to your PC.