I just received my new set of Powerbase Soar fins. They are the DL template which is the go to template for a vast number of pro surfers, including Taj, who use glass ons. Owen Wright is also a Powerbase team rider and using the larger DXL template fin and the Powerbase fin boxes.
There are 3 materials available. Electra, which is the softest flex pattern, Amour which is the medium and apparently very much like glass ons, and then the Ceramic material which is stiffer again. I believe it is similar in feel to G10 material. I went for the Armour tech.
The fins have a flanged base like that of a glassed on fin and pull down into the plugs as you screw them in which prevents the movement at the base of the fins. That should lead to a more immediate response, increased drive etc.
Here's a crappy photo, the lights a bit shit at home but I'm sure you can see better pics on the web pages.
I haven't tried them out yet but will post some feedback once I have.