I've certainly seen it reported that there's more elevation than at Beijing, could be wrong, the point is that it doesn't really make much difference how big the hill is, it's going to have more money spent on it than any MTB course in the country, particularly considering it's not gonna be very long! Beijing was 4.6k per lap.
but Margam is a short blast down the M4 and the sailors do get to go to Dorset
Margam is the opposite side of the country! The sailing's at Weymouth as there was no practical location closer, that's not the case for the mountain biking. Also, how many spectators did you see on the course at Margam? Jim Whenman and the Wiggle chap in the second feedzone, and 2-3 at the bottom of the muddy chute, how exciting for an Olympic event!
Never mind, if no one wants to go it'll be easier for me to get a ticket and watch the best riders in the world duke it out on an exciting course!