One of the problems with the standard jib cleats is they are very difficult to release in winds over 20 knots. They can be replaced with Spinlock PXR swivel base cam cleats that enable you to release them under load.
There are two sizes of cleats available (PXR0206/SW for 2-6mm line and PXR0810/SW for 8-10mm line) which are a direct replacement for the standard Weta jib sheet swivel fitting and use the same holes in the deck. You can access the bolts to release the old cleats from inside the hatch (Early boats had jib cleats that were screwed into place). You then need to remove the cam mechanism to expose the holes on the swivel base of so you can pass the bolts through by undoing the screw which is inside the unit (be careful not to loose the captive nut on the bottom).
Download official installation instructions and drill template here
Benefits: Jib sheets can be released and catch under any load.
Cons: It takes a while to remember to flip the cleat up and down to get it to grip/release. Cleats are quite expensive.