Hello!

> On a usage note, I was surprised that the patch causes automatic insertion
> of top and bottom rules even when the org table doesn't use ascii
> top/bottom rules. In fact, if you use "|-" to put ascii rules on an org
> chart using this patch, you get double rules.

Disclaimer: I did not test this at all, but am interested in a convenient
booktabs support, too.

I think it is reasonable to put the top and bottom rules automatically, as
booktabs somewhat defines that as the intended look.  So it would be redundant
to require a |- on top and bottom for all tables on the org side.  I even
think that org tables with top and bottom rules do not look good, because the
vertical lines do not stop at the horizontal lines (from a visual point of
view).  This way it looks like is a very small empty table line above and
below the table.

Daniel