Look how many people here put down Force Fins and yet they have never used them!!!.
Can you please quote the posts you're talking about?
I have re-read the whole thread and I only found this one post that could be what you're talking about. Where he said this:
No matter what the fin design is, the basic law of physics still applies: Force = Mass * Acceleration, and FF are just too lightweight. I have been taught well that it is best to minimize your body movement underwater. That's why I'll stick with jet fins. Scuba diving is not swimming, and you'll need to kick more frequent with FF to move around. So, it is up to your style and things you do underwater.
But that's the only post I can find that I can construe to denigrate FF fins and be from some who (maybe?) has not tried them. He doesn't actually say whether he tried them or not.