These look really good. The videos are what sold me on wanting to get them, especially the Mountain Trail video. Just need to refigure my budget now
I understand what you were getting at with not wanting to do a swamp scene, but you may want to Google images of wetlands. They might be a good compromise and are similar to swamps, just with fewer trees.
I would really love to see a couple of farmland sets, with freshly plowed fields and crops/wheat growing on them. Perhaps one set with two settings or a grass/wheat prop? Another idea might be Asian rice paddies?
Finally, thanks for the tutorial on depth of field.
Edit: If you made a wetlands set with water, SuperGJ may be able to convert it into a swamp by adding trees...