1+ on the Mares Avanti Quattro. I have had my pair for about 3 years now. Only fin I use. Put the new bungie straps on this summer making them even better. My partner went through Slingshots, Atomis spits, F1's (monster heavy) and finely bought the Mares Avanti Quattro Plus that come with the bungie strap.
Mares Avanti Quattro Plus Open Heel Fin at LeisurePro
Mares Avanti Quattro Plus Open Heel Fin at LeisurePro