Terrain chunking works very well with LOD. We just haven't implemented it because our tests have shown no significant frame rate improvement. However this might change with larger terrains.

Patching or "geomipmapping" was one of the first algorithms for terrain optimization, and is for various reasons not suited for modern 3D hardware. We tested it once with an early A5 version. It was slower than no optimization at all. I don't think that anyone still uses it today.

Chunking is by far the best terrain algorithm for T&L 3D cards. The only thing that we could improve is implementing caching, and possibly LOD, for extremely huge terrains.