Man, anybody who's read through all this meta-thread crap just to get to this point has probably forgotten about the main subject of the thread, but here goes...
To me the main things I'd be concerned about if I was considering these fins is, do they actually work as intended? I mean, do they go up and down without a too much bother, and do they stay where you put them?
Will they last? I've heard they look pretty strong, but any additional moving parts on an item that gets so much abuse is probably asking for trouble. Even if they last a good long time, I bet they won't last as long as a simpler fin.
Just from looking at the pictures, the actual fin design looks like a lot of other scoop-type paddle fins. I'll bet they'll come out with a split fin design before too long. They'll have to pay royalties for that, right?
As for the guy from Belize who couldn't understand the need for these fins, that's understandable. I just got back from there (awesome!), and if you want to do a shore dive down there you'll be hiking about a half a mile before it gets deep enough to float! They make a lot more sense around where I dive, which brings up another thought...
Can you actually walk on slippery rocks in them? What's the sole like? If it's rough enough to get traction, doesn't that add more drag? I bet they have a lot of drag anyway.
Who knows? Maybe in a hundred years flip fins will be standard items.