I wanted to share a quick video showing that you can definitely do some environment sculpting work within Blender. If you combine your alpha packs with the alpha manager add-on, it becomes really sexy.
Here is the link for the alpha manager add-on: https://github.com/Ryxx/Sculpt-Alphas-Manager
To get a similar Zbrush feeling with DragRect mode, you need to adjust few settings in the Draw brush.
1/ First, adjust the mode texture mapping option to "Area Plane".
2/ Then, adjust the stroke method to "Anchored".
This is it, you are good to go.
For the ones who purchased the 3Dbrushes Sand Desert, you will notice I released an update with .tiff format so it will make your life easier to use them in Blender. I hope it helps. Happy sculpting ;)