I've used these fins, well one of them anyway and I can tell you they're fast all right and comfy

and I'd gladly keep them if I lived in a windier place and sailed smaller gear. Sadly I've got the Sydney east coast doldrums to contend with along with my 100kgs, so most of the time I'll sail with my 9.5 on my 80 wide slalom with my 47 Select AW fin but only when it's really weedy otherwise I prefer to use a 46 to 50 slalom /race fin.
I hate weed fins and will only use them when it's absolutely necessary, I had a JP 36weed fin, it was too small for me but having said that if I was on a small slalom board with a 6M or smaller I would probably be fine but unfortunately I hardly ever use gear that small because it's generally not windy enough around here for me

For gear to be suitable for the user it's a matter of physics, ratios and personal tastes.
I never use what others are using because I'm usually heavier than anyone else, I need everything bigger.
Have a good look at these fins, the swept back rake equals minimal drag
These are high wind weed fins for really weedy, windy places like the Canadian lakes they were designed for.
If you want a high wind weed fin look no further.........