Omg, this is crazy... getting dizzy by only watching this.

I used to have dreams of this type of flying - almost exactly like this.  But that was probably because I was heavily into Hang Gliding.  I flew with some of the world's champions and really enjoyed the sport in the 70's and early 80's.  But I never had any desire to skydive and this new sport is really an off shoot of skydiving.  Hang Gliding you were doing about 25 MPH to 45 MPH although with some gliders you could do a little faster and maybe as slow as around 20 MPH before worrying about stalls.  But this sport looks like they are doing a minimum of 70 MPH and an average is around 100 MPH most of the time and from the looks of how close some of these guys come to trees and rocks it seems pretty nuts.  I used to scrape within a foot or so of some cliff faces and maybe even take out a small bush or plant sometimes in trying to stay up in light wind but I was only doing 20 something. 
 
  I think I'd like to have tried this sport but I'm afraid my ears popping from the rapid descent might have been a problem for me.  I used to get into thermals that had my variometer pegged at over 1200 feet per minute up and that bothered my ears.  I'm sure these guys are doing more than 1200 feet per minute descent.  That was a great video but some of these guys are really pushing the limits by how close they come to trees and ground objects.  Perhaps they are getting 'ground effect' where the compression of air from their wing close to the ground gives more lift than if they were farther up.