Thanks for the comments guys.
This image does use that GI technique I've been working on which uses a balance between sunlight and background light to light the scene simultaneously (usually mostly one or the other as you can't do both without a big light mess). By default, TG2 is setup to use the sun to light up the scene first and foremost, then there is secondary light from the environment - which is what happens in real life. The GI technique is a "quick and dirty" way to get more of an overcast diffuse effect with more control at the expense of not being "true".
Since the GI technique is artificial, it takes some time to dial in for each image, requiring manual tweaks to get just right. This image was a challenge for this, but worth it.
As for the trees, I went ahead and bought the entire Onyx Garden Suite and I am very impressed!
For surfacing on the pines, I came up with a 3 point lighting method to dial things in perfectly. For example, take a tree and render three different images with the sun in 3 different locations around the tree (One with the sun behind the camera, the other 90 degrees to the camera, and the last directly in front of the camera). Take a look at each render, adjust colors, reflectivity, translucency, etc and keep dialing each in until all three angles make the tree look superb. I was surprised at some of the values required to do this. But from then on out, they look really nice in most lighthing conditions.
By the way, you can do the same with surfaces and other objects. In fact, one new surface I've been using uses 2 reflective shaders, each with different values in reflectivity and roughness! Pretty fun stuff.
