Once you get past the initial "Whoa!" when you see the node interface its actually not that steep a curve. You can create some very good renders without having to go too deep into the nodes and functions. You can build up the surface shader layers much like you did with TG 0.9.xx with the added functionality of a much better distribution system and various projection modes for the bitmap textures. Then on top of that you can add multiple populations, enabling you to add grass and trees, in quite remarkable numbers too.

I use Vue, Terragen 0.9.xx & TG2 plus Carrara pro and after a bit of practice the interface of TG2 is no more difficult than any of the others. A nice function is that you can project masks through the camera so you can limit populations to what you can actually see, thus cutting down considerably on the number of instances required. Speed wise, the render engine is yet to be optimized and made multi-threaded but both of those will be done prior to release of the final versions.