If the discussion is on the usefulness of vc-region-history, then it has been very useful for me.
That's very far from my experience. I frequently need to investigate
fragments of code which have very long histories, and "log -L" always
gives me the full picture, even when the code in question changed
significantly, right to the commit that first introduced the code.
Perhaps the secret is in choosing the appropriate region. I normally
try to submit the entire function where the code lives, and it works
very well.
--
Kaushal Modi