Actually SteveA, 'spending weeks' is really the best way as what you may consider good and optimised may only be relevant to your project.

Generally though there are some problems with multitexture terrains when applying stencil shadows to the character, some multitexture seems to disable or cloak shadows.

Chunking is good if you are not deforming terrain with explosions or vehicle crashes.

Mipmaps are your friend and good terrains can be accomplished with an intelligent approach (work at it rather than using ANY detail images)

Shaders should in my opinion be used very sparingly and in tightly controlled conditions.

One of the best methods for me is to individually texture each componant of the landscape like cliffs, scree slopes, river beds and so on then mip map to get an effect so close to multitexture that it looks as though it has a multi texture applied. The result is good frame rates.

Not what your looking for perhaps but essentially the way it is from my point of view.

Hope I havnt confused the issue here,

Cheers...