I think this looks really cool and useful and I will probably give it a try. I don't know anything about GTD, but I use Ta-da Lists extensively and this looks like a nice step up for me. I would miss the ability to share my lists with others, but I could live with that. Handling text input intelligently is very nice.

The audio on the demo video is terrible. I had to crank the volume on my PC to make it out. I would consider re-recording it, and getting some help from someone who knows how to record sound.