It also depends on what particular kind of vetiver is used in the composition.
Indonesian vetiver is earthy, smoky and a bit woody.
Indian vetiver is the indonesian vetiver on steroids - its the most earthy of them all.
Sri Lankan vetiver is almost entirely woody .. no earthiness to be found here, it smells the least vetiver like.
Haitian vetiver smells clean, green, slightly citrusy, with subtle shades of the typical earthy aroma. Its the most pleasing to smell by itself.
As you mention, not all vetiver fragrances are created equal or smell the same. From what I know, Lanvin Vetiver and Original Vetiver use the haitian vetiver extract instead of the more earthy indian/indonesian variety - they intend to provide a refreshing interpretation of this classic note, and to me they largely succeed. Some even find Original Vetiver to be too "earthy"! When I am in the mood for some raw vetiver goodness, I simply grab a fragrance with a more earthy rendition of vetiver.
Different vetiver ingredients, different blends ... theres a vetiver for everyone out there!