Not sure I like the way the laptop is held down - makes the whole thing unnecessarily wider and looks kind of clunky in practice. Hopefully the screws are captive - trying to fiddle around with them in an emergency wouldn't be much fun if they weren't.
For studio work, a Tallyn's laptop deck
is hard to beat.
For outdoors use I've toyed with the idea of getting a 3/8" hole drilled and tapped directly in the chassis of my MBP, so I could attach a RRS plate. Failing that I could just epoxy it on, and then attach it to a ball head or whatever using a standard clamp - sure would save a lot of weight compared to the hunk of metal shown in the video.