In reply to shaun stephens:
Although building a direct system may appear to make it easier to escape but in reality it wont make a lot of difference and under most circumstances is unnecessary. The advantages of using an indirect belay usually outweigh the need to be seperate from the system.
Belaying using a belay plate in a direct system is more difficult because it needs to be in front of the belayer and tends to flop about - an italian hitch or magic plate works, but not suited to belaying a leader. If you try to use a direct system on a multi pitch crag you will soon find it is not suited to belaying a leader unless the upward pull has been planned for - this creates unnecesary faff on is not as safe. If you are not part of the system you add no strength to the system. It is much easier to give assistance to a second if you are part of the system - like on the video. All the disadvantages above combined with the frequency for escape to be required mean folk typically use an indirect system, its just easier, usually safer, and more flexible. The exception being when guiding or instructing when a direct system is often used but thats not just because you can escape from it.
Being able to escape only has any relevence if you know what to do next, on a single pitch crag the answer is usually lower them to the floor. If you have the skills to sort out the problem that has caused you to need to escape on a big crag you will not find escaping from an indirect belay using a couple of prussics and a sling a problem.