ran a quick experiment to see what level of texture detail could be generated in a unique terrain using L3DT as the terrain source. The heightfield is 1024 x 1024 px with a vertex spacing of 10 meters. Nothing special here, just the normal random designmap created by L3DT without any editing. This was used to create three finished tiled textures as described below.
Terrain #1: Texture map sized same as heightmap (1024 x 1024). Each texture pixel covers 10 meters. Atlas size: 42,585kb. Image is here: http://i40.photobucket.com/albums/e216/zedd10/StewartE1T4VPC2548.jpg
Terrain #2: Texture map created at 16k x 16k. Each texture pixel covers 0.625 meters or about 2 feet. Attributes map, Lightmap and texture are all 16k x 16k. Atlas size: 77,417kb. Image is here: http://i40.photobucket.com/albums/e216/zedd10/StewartE1T4VPC2548x16.jpg
Terrain #3: Texture map created at 32k x 32k. Each texture pixel covers 0.31 meters or about 1 foot. The attributes and lightmap were not regenerated at 32k and were left at 16k. You'll notice a black grid on this terrain. It is probably from the mismatch in map sizes. Image size: 171,420kb. Image is here: http://i40.photobucket.com/albums/e216/zedd10/StewartE1T4VPC2548x32.jpg
I plan to try 4x and 8x textures also. I'll post these results when they are done.