great idea and great execution (from what I can see). The narration idea is very original with the video intro. But I do agree with other commenter that it was odd to have to pick a narration. 
I'd suggest you pick the one you like best or which best shows off the capabilities, and just use that, or rotate through them. 
Even though you went through the effort to create the different videos, it is best to keep something like that simple for the user.