Could you try it with the following two resource packs, and get comparison pictures from the same perspective as the last two images you had there (the plains biome)?
Also, for a final comparison, again in the plains biome, could you try temporarily replacing all of the spruce leaves with one of the custom spruce-based leaf blocks (e.g. the juniper berry leaves) and get a screenshot of that, using the normal resource pack?
Dropbox
www.dropbox.com
Dropbox
www.dropbox.com
Also, for a final comparison, again in the plains biome, could you try temporarily replacing all of the spruce leaves with one of the custom spruce-based leaf blocks (e.g. the juniper berry leaves) and get a screenshot of that, using the normal resource pack?