Paul,
If you want a kitesurfing DVD then go for Ten4, seriously good VFM, 80mins for £17.95, all the top riders.
Allowing for the fact that a lot of the material is repeated, and about 5 minutes of the film is made up of really old footage from NZ shot on very dated equipment (nothing like broadcast quality in places), there is only about 20mins of footage on Ground to Air.
Still bought it though, the footage that is on there is superb, I know I couldnt do better, but tbh I'm not sure it's worth £1 a minute...