In reply to jimtitt:
Stick with it a little and get used to the configuration. I'm the first to admit I'm a little slow at mechanical engineering and I took a few goes to get confortable with the Megajul. Now I think it's the dogs. Works great with a fat Petzl carabiner with a thick rounded profile.
Trying to copy the fellas in the video isn't a lot of help. Instead, protecting a leader, try setting it up like a regular tuber (green handle foremost) and keep the dead rope snapped back at all times. It WILL lock almost instantly with no effort on your part. You can get really fast taking in or feeding out with it. And the locking feature saves effort and stress.
The video doesn't show how to bring up a second but that is again a matter of setting up like a tuber and pulling on the dead rope which inverts the device (ie it turns upside down) and then pulls easily though, while locking instantly if any weight is exerted on the live rope. I'm a convert.