You dont need to use the complexity of memblock terrains to achieve good effects with DBPro, particularly if you find them too complicated then dont worry about them.
I have been using 3D mesh tiles to great effect, it is very easy to do and allows for the use of LOD meshes. Landscapes created in this way look good and are so large they can easily make a game world too large to populate with interesting things.
To put that in perspective I would say Everquest has one of the largest game worlds of any computer game if not the largest and already I can produce a game world a few hundred times it's size... I wont release a game with that of course because I dont want to be the mug that sits there and puts interesting things all over it!
Really it is like making a 2D map all over again, except using 3D meshes as the tiles. Enhancements could include LOD as I have done, retexturing on the fly, and unlimited scenic objects. All without having to deal with the complexities of memblocks.
Here's some screenies of where I am at with mine at the moment. For the time being I am using your tree model from OIE Van-B, my first effort to model a tree hardly did the landscape justice so I used yours to work with
I also have dabbled with memblock meshes, I have one part developed that can recreate any part of Earth from USGS data, I just preffer this method myself because it is faster in runtime.
If you opt for the mesh-tile route there are a few things to consider.
1. You must have a common edge height on your tiles, therefor you may wish to have much larger tiles than I am using at the moment.
2. In order not to increase the seemline between the tiles you should place the next row of vertices in at the same or similar height so that the normals do not create a dark/light line along your terrain.
3. You can position the second row of vertices quite close to the outside edge to reduce the impact this has on your terrain altitudes.
4. Low contrast textures along the tile edge make a better seem.
5. Don't get carried away and make a terrain too large, of which I am guilty as charged.
God created the world in 7 days, but we're still waiting for the patch.