I think those low-poly trees could be a real alternative for Gen’s generated ones, which ususally are quite heavy and slow rendering time a lot.
After resolving the annoying alpha-shadow bug ( http://blenderartists.org/forum/showthread.php?t=81390 ) it seems that this method of tree-creation is good enough for fast projects.
Concerning tree modeling - i use tree[d] (gile[s] addon for tree modeling) - it’s freeware but created files could be opened only in gile[s]. Then i save it to obj file and reopen in blender.
Textures are all hand-made - my digital camera helps me a lot. The main tip is to make a picture of a small tree with a plain white background (usually cloud sky), then any editor capable of creating alpha-mask.
Here is a download of packed .blend (1.1MB):
I really think this could be usefull.
Thank you for any feedback.