Ian,
The tally was taken on the final night and Humewood won by a couple of votes. I preferred Durban and did not feel it was a close contest. Humewood was incredibly enjoyable and would make a wonderful home club.
As Tom mentions, Durban suffers a bit from expectations, but also from a dramatic mix of holes. Durban has 10-11 holes that are great, with nine of them on really interesting, heaving land. The negative comments have always related to the "flat holes", which are the weaker holes. First, these holes are not as "flat" as people make them out to be (see Mark's photo of the tenth). Secondly, while they are not over dunesland, they are for the most part strong.
Durban suffers because of comparison of its best to worst holes. Not unlike Pebble Beach, whose detractors always point to the weak holes as a sign the course is somehow lesser. Like Pebble, Durban has more than a handful of world-class holes and a few, which although not bad, would never be considered of an elite level.
Humewood by comparison has one world class hole and a bunch of rock-solid ones. I think that were Humewood's highs higher, the lows (17 and 18 among others) would also stand out more.
Our straw vote was not entirely scientific and upon reflection, I know a vote today would favour Durban, for the reasons Tom alludes to.