Why would you want to go Full-Frame for video? Full frame is for photography. The 1.6x crop factor is ideal for video, because it's exactly what you see in a Panavision or Arri 35mm motion picture camera. It's been like that for decades.
Basically, if you want to shoot stills of action sports, get the 5D. If you want to do video, get the 7D.
And believe me, you can plenty of Shallow DOF on the 7D.
Basically, if you want to shoot stills of action sports, get the 5D. If you want to do video, get the 7D.
And believe me, you can plenty of Shallow DOF on the 7D.