To answer the question Pappenheimer and I had, I think this is the deal:

--The Earthsculptor editor is a lot better than the A6-based one in IceX2.0. It has multiple undo, it's very quick and intuitive, easier to navigate, and doesn't crash.
-- The output from earthsculptor using the blendmaps is a lot easier to tweak manually in paint programs, working with the bitmaps directly.

-- IceX 2 is really quick in terms of exporting a WMB, it is not necessary to convert all these files and get them in place for a separate shader. IceX is a lot easier.
-- I can't see any difference in quality between the two
-- IceX 2 can also do 4 textures
-- IceX 2 can divide a terrain into multiple chunks, even if it's a polymesh/mdl terrain (that's a big one in my opinion)
-- IceX2 can output both high quality multitexture terrain -and- low quality single texture (composited) terrain. I find that useful for using the low quality as a temporary model in my 3D editor, so I do not need a fancy shader in my modelling environment, then substituting in the high quality version when the game is built.
-- IceX 2 can also automatically set water
-- Not sure if Earthsculptor can do this, but IceX2 has a great road feature.
-- IceX 2's texture blending feature with sliders is really easy.

I prefer IceX 2, but it crashes all the time and there isn't an undo feature those two things really suck eggs. But it's easier and quicker. But harder to tweak manually because all the blendmaps are internal textures to the actual mdl file.

I think the best tool would be a non-A6 based IceX 2 editor that does the same thing, but with multiple undo and stability, and some slightly better navigation tools, with easy to read external files and the easy export it already has. Personally I'd stick with Icex2, and saving frequently to avoid the crashes and be able to go back once in a while in lieu of undo.

I hope that helps if anyone is curious about the difference between these two approachs! I'm not saying one is better than the other, I think they're about equal overall, but nearly polar opposites in strengths and weakness.