Attached is one of my favorite terrains that has some good displacements. It is a culmination of other files I have used combined with my own experimentation.
The two plant models (pines) in the file are those available here at the forum that were offered by Walli (the plant pack). I have changed the pine needles color and brightness in Photoshop which better suit the lighting and terrain color in the scene. Included is dandelO's 10M cracks file.
If you have any questions, send me an e-mail.
Enjoy.