I love this concept, 37signals way back in the day used to do these UX teardowns and rebuilds via http://37signals.com/better and that had a lot to do w/building their rep for UX expertise

A couple of notes from conversion side:

a) Better - Your inclusion of a visually descriptive image is an improvement vs. pic of the girl - maybe as a keyframe since the vid is an important visual demo.

a) Draw - Original site compatible w/1024x768, your new one less so. Their audience is probably tech savvy and not @ 1024x768 but as a rule better safe than sorry and 1024 requires an element-economy that can sharpen your messaging anyways.

b) Worse - Your headline is more entertaining, but less on point. You've incorporate their original as a sub-headline but you'd be surprised how many people will simply overlook that.