Very generous offer Bazuka! This test scene is one Onyx tree and a couple from Evermotion so unfortunately I can't share it for testing in its present state :(
I'll see what I can come up with though. Unless you yourself have a royalty-free tree model anywhere?
If I can source a good royalty-free model (or if anyone has any feel free to upload) I'll upload it for anyone to play around with and compare notes.
The tree model itself is important, as using leaves with slight curvature (like you can output from Onyx) is important for realistic specular roll-off, as leaves are never flat.
Here's a raw render saved straight from the VFB. Sun+Sky at an afternoon angle default CIE Clear, Vray Physical cam default settings,
Above, but with very quick post work in Photoshop:
and the colour mapping (all diffuse textures have Vray texture input gamma 2.2 attribute applied. I have left reflection, translucency etc textures alone)