I use git delta to achieve most or all of the diff changes on the command line. I highly recommend the tool over writing your own.
I would love it to have support for writing inline messages in the
output somehow. Then it would be possible to write some binding script
that would sync those messages with code review comments on popular
sites like GitHub or Bitbucket. I would very much prefer it that way
instead of using a webpage.
I have expected the author would show a tool, such as the one of Jane Street that could integrate with GitHub, Gerrit, ReviewBoard, whatever.
But the author doesn’t.
In fact, skimming the article, I missed the information on how the author feeds back his insights in the code-review tool of choice.
If he simply uses the vimdiff (with some bells and whistles), then I think many people (including myself) do that for years, but simply because those people know so well their command-line tools, that they are way more efficient using them than the code-review tool of choice.
On the positive side, I liked the idea of creating a dependence graph of the files in the patch, so it drives the code-review process.