Turbo - it certainly is; I love working around the ridiculous restrictions inherent to the work.
So far I've had mixed success with pushing the contrast, as the textures tend to get a bit harsh on the eyes. Still playing around to find a good balance, though. So far just about all the textures so far have incorporated hue shifting to varying degrees, but for the most part I've had to reduce the saturation on the finals in order for the vertex lighting to have any discernable effect on the color (eg, the blue shadows and warm sunlit areas).
Stealth - no worries. To be honest I was initially a bit unsure of whether to post this here, so I ended up clearing it with ptoing first, though I
was warned that it may not receive a very warm welcome.
TakaM - thanks a million for that screenshot. The trees in the previous shots were built with my mindset still in the "workable silhouette from all angles" mode, and your post has kicked me in the face and woken me up. I've played a bit with stacking and staggering a few non-planar quads on the same tree trunk, and the results have been very promising. The following shot is with a placeholder foliage texture (I just wanted to play with the alpha to see how everything would look, so it's rather indistinct right now). I'll play with the foliage and see what I can come up with.
Here's a shot of the trees with circles for foliage to show the structure (varying colors are being handled by vertex lighting):
circle trees!