Tagger... I have been experimenting with the Nike shape, as well, although not an exact copy since all I've ever seen are pics. I do a couple things different, like where the lead goes and how the slope is cut, but there's still a resemblence.
Like you, I thought it would be a swimmer until I tossed it in the water. It'll swim, without any lead, even with a darter face... the way I started out playing with it. Once you started this thread, and the xray showed up, things got interesting.
I went to a straight 38 degree slope, and a nice slug of lead in the tail, and as you suggested the lure sits in the water like a popper. If and when I finally got its face in the water, it came in virtually straight.
So I started playing with the slope and redistributing the weight. The latest proto is hard to describe, because it neither swims nor darts, but glides in a wide "S", sometimes as much as 2-3 feet off center before it swings back just as it looks like it might roll out. It will be interesting to see if final coating of epoxy changes things, but it's been fun playing with it.