This thread has what looks like interesting information, but I don't read Chinese.
http://hfsword.com/bbs/viewthread.php?tid=17059
There is a very nice example of a Tang dao in excavated condition with a medial ridge. The tip is unclear, but it is rounded in shape. Would a tip have to be a straight line to be considered faceted, or would you consider a separately polished curved tip faceted?
Josh