I have. I got about a dozen of C-Drive sets (various sizes, thrusters, quads, twins, ...). They were my favorite fins until I switched to using only Quobba fins.
What the C-Drives provide is insane grip at low speed with the huge base cord length. You can thus get a turbo boost out your first bottom turn, even on weak, slow waves. But at speed and in the power, the thin tip avoid building up too much lift, so the fin does not have a tendency to "foil" and stiffen the board underfoot like keels can do.
I found them especially useful on fast boards with wide tails (Fishes, Twin fins, Simmons), opening up their range immensely. But I know some much better surfers than me not liking them because they were bothered by the dual personality of the fin while threading turns. They are also great for people struggling with the row effect of small performance SUP as they provide grip even at paddling speeds. They also have a bit more drag than good standard fins.
If you want to experiment, I would recommend you also try:
- S-Wings: the ultimate for a smooth, fluid, shock-absorbing ride. Especially useful in bigger waves and chop. Makes carving a dream, kind of sking in deep powder. But a bit of added drag.
- Quobba: the fastest fins, the lowest drag, and great hold: they kind of raise the upper speed limit of any board, allowing you to seek trajectories on waves you would not have attempted before. I now use only them exclusively.