Far less polygons and splitting a mesh into segments for LOD wouldn't screw up the appearance. In the case of vertex alpha, there'd be a very (and I mean very) noticeable seam in the texture blending.
Ultimately, texture splatting would probably end up being more efficient (my former idea of textures using 2.2mb per splat was incorrect) in the long run due to it not having the disadvantages that vertex alpha-blended terrain present with (distance-based, typically) LOD.
Either way, it's a preference thing. I think exploring alternatives such as this would be a wise idea.
Ultimately, texture splatting would probably end up being more efficient (my former idea of textures using 2.2mb per splat was incorrect) in the long run due to it not having the disadvantages that vertex alpha-blended terrain present with (distance-based, typically) LOD.
Either way, it's a preference thing. I think exploring alternatives such as this would be a wise idea.