I haven't seen the video, so take this for what its worth. But I have seen a number of Marine specific self assenders and to be honest have never really felt they were very good. They all seem to me to rely too much on using arm strength and questionable practices to secure the line off.
Years ago I borrowed a self assender rig from a friend who was a rock climber, and have never looked back. These rigs are simple, use leg muscles rather than arm, and do not require storing an extremely long line to climb the mast. In my experience they are much better designed than Marine systems, and to be honest I feel like if a system is designed by people to use every day (rock climbers) is good for them, it is probably better thought out than systems used by sailors who use them infrequently if at all.
Any of these systems to me take less effort to operate, and are recommended (At least by Black Diamond) for this purpose.
Take a look at:
http://gripped.com/2009/07/sections/rack/ascenders/